From 2ed60fdcc183cf5742f9042807727a03b2e46fdc Mon Sep 17 00:00:00 2001
From: Mathias STRASSER <contact@roukmoute.fr>
Date: Wed, 4 Feb 2026 00:11:58 +0100
Subject: [PATCH] feat: Audit trail pour actions sensibles
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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Story 1.7 - Implémente un système complet d'audit trail pour tracer
toutes les actions sensibles (authentification, modifications de données,
exports) avec immuabilité garantie par PostgreSQL.

Fonctionnalités principales:
- Table audit_log append-only avec contraintes PostgreSQL (RULE)
- AuditLogger centralisé avec injection automatique du contexte
- Correlation ID pour traçabilité distribuée (HTTP + async)
- Handlers pour événements d'authentification
- Commande d'archivage des logs anciens
- Pas de PII dans les logs (emails/IPs hashés)

Infrastructure:
- Middlewares Messenger pour propagation du Correlation ID
- HTTP middleware pour génération/propagation du Correlation ID
- Support multi-tenant avec TenantResolver
---
 .github/workflows/ci.yml                      |   7 +
 .gitignore                                    |   3 +
 Makefile                                      |   7 +-
 backend/config/packages/messenger.yaml        |   8 +
 backend/config/services.yaml                  |  13 +-
 backend/migrations/Version20260203100000.php  |  65 ++++
 backend/migrations/Version20260203100001.php  | 118 ++++++
 .../Event/CompteBloqueTemporairement.php      |   2 +
 .../Domain/Event/ConnexionEchouee.php         |   2 +
 .../Messaging/AuditLoginEventsHandler.php     |  76 ----
 .../Security/LoginFailureHandler.php          |  35 +-
 .../Shared/Application/Port/AuditLogger.php   |  65 ++++
 backend/src/Shared/Domain/CorrelationId.php   |   9 +
 .../Infrastructure/Audit/AuditLogEntry.php    | 101 +++++
 .../Audit/AuditLogRepository.php              | 188 ++++++++++
 .../Infrastructure/Audit/AuditLogger.php      | 215 +++++++++++
 .../Audit/CorrelationIdHolder.php             |  62 +++
 .../Handler/AuditAuthenticationHandler.php    | 106 ++++++
 .../Console/ArchiveAuditLogsCommand.php       | 181 +++++++++
 .../AddCorrelationIdStampMiddleware.php       |  35 ++
 .../Messenger/CorrelationIdMiddleware.php     |  60 +++
 .../Messenger/CorrelationIdStamp.php          |  22 ++
 .../Middleware/CorrelationIdMiddleware.php    | 113 ++++++
 .../Api/ActivationEndpointsTest.php           | 102 +++++
 .../Api/RefreshTokenEndpointTest.php          | 105 ++++++
 .../Api/Controller/LogoutControllerTest.php   | 305 +++++++++++++++
 .../InMemoryRefreshTokenRepositoryTest.php    | 249 ++++++++++++
 .../Security/LoginSuccessHandlerTest.php      | 331 ++++++++++++++++
 .../Unit/Shared/Domain/CorrelationIdTest.php  |  16 +
 .../Audit/AuditLogEntryTest.php               |  81 ++++
 .../Audit/AuditLogRepositoryTest.php          | 219 +++++++++++
 .../Infrastructure/Audit/AuditLoggerTest.php  | 354 ++++++++++++++++++
 .../Audit/CorrelationIdHolderTest.php         |  87 +++++
 .../Audit/CorrelationIdMiddlewareTest.php     | 188 ++++++++++
 .../AuditAuthenticationHandlerTest.php        | 200 ++++++++++
 .../Console/ArchiveAuditLogsCommandTest.php   | 224 +++++++++++
 .../AddCorrelationIdStampMiddlewareTest.php   |  94 +++++
 .../Messenger/CorrelationIdMiddlewareTest.php | 212 +++++++++++
 38 files changed, 4179 insertions(+), 81 deletions(-)
 create mode 100644 backend/migrations/Version20260203100000.php
 create mode 100644 backend/migrations/Version20260203100001.php
 delete mode 100644 backend/src/Administration/Infrastructure/Messaging/AuditLoginEventsHandler.php
 create mode 100644 backend/src/Shared/Application/Port/AuditLogger.php
 create mode 100644 backend/src/Shared/Infrastructure/Audit/AuditLogEntry.php
 create mode 100644 backend/src/Shared/Infrastructure/Audit/AuditLogRepository.php
 create mode 100644 backend/src/Shared/Infrastructure/Audit/AuditLogger.php
 create mode 100644 backend/src/Shared/Infrastructure/Audit/CorrelationIdHolder.php
 create mode 100644 backend/src/Shared/Infrastructure/Audit/Handler/AuditAuthenticationHandler.php
 create mode 100644 backend/src/Shared/Infrastructure/Console/ArchiveAuditLogsCommand.php
 create mode 100644 backend/src/Shared/Infrastructure/Messenger/AddCorrelationIdStampMiddleware.php
 create mode 100644 backend/src/Shared/Infrastructure/Messenger/CorrelationIdMiddleware.php
 create mode 100644 backend/src/Shared/Infrastructure/Messenger/CorrelationIdStamp.php
 create mode 100644 backend/src/Shared/Infrastructure/Middleware/CorrelationIdMiddleware.php
 create mode 100644 backend/tests/Functional/Administration/Api/ActivationEndpointsTest.php
 create mode 100644 backend/tests/Functional/Administration/Api/RefreshTokenEndpointTest.php
 create mode 100644 backend/tests/Unit/Administration/Infrastructure/Api/Controller/LogoutControllerTest.php
 create mode 100644 backend/tests/Unit/Administration/Infrastructure/Persistence/InMemory/InMemoryRefreshTokenRepositoryTest.php
 create mode 100644 backend/tests/Unit/Administration/Infrastructure/Security/LoginSuccessHandlerTest.php
 create mode 100644 backend/tests/Unit/Shared/Infrastructure/Audit/AuditLogEntryTest.php
 create mode 100644 backend/tests/Unit/Shared/Infrastructure/Audit/AuditLogRepositoryTest.php
 create mode 100644 backend/tests/Unit/Shared/Infrastructure/Audit/AuditLoggerTest.php
 create mode 100644 backend/tests/Unit/Shared/Infrastructure/Audit/CorrelationIdHolderTest.php
 create mode 100644 backend/tests/Unit/Shared/Infrastructure/Audit/CorrelationIdMiddlewareTest.php
 create mode 100644 backend/tests/Unit/Shared/Infrastructure/Audit/Handler/AuditAuthenticationHandlerTest.php
 create mode 100644 backend/tests/Unit/Shared/Infrastructure/Console/ArchiveAuditLogsCommandTest.php
 create mode 100644 backend/tests/Unit/Shared/Infrastructure/Messenger/AddCorrelationIdStampMiddlewareTest.php
 create mode 100644 backend/tests/Unit/Shared/Infrastructure/Messenger/CorrelationIdMiddlewareTest.php

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6a54619..7d0ddb8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -193,6 +193,13 @@ jobs:
           # Generate JWT keys if they don't exist (required for login/token endpoints)
           docker compose exec -T php php bin/console lexik:jwt:generate-keypair --skip-if-exists
 
+      - name: Create test database and run migrations
+        run: |
+          # Create test database (Symfony adds _test suffix in test environment)
+          docker compose exec -T php php bin/console doctrine:database:create --if-not-exists
+          # Run migrations to create all tables (including audit_log)
+          docker compose exec -T php php bin/console doctrine:migrations:migrate --no-interaction
+
       - name: Show backend logs on failure
         if: failure()
         run: docker compose logs php
diff --git a/.gitignore b/.gitignore
index 7148b70..b49ba46 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,3 +13,6 @@ npm-debug.log*
 yarn-debug.log*
 yarn-error.log*
 pnpm-debug.log*
+correlation_id
+tenant_id
+test-results/
diff --git a/Makefile b/Makefile
index 9b41330..3b00bc7 100644
--- a/Makefile
+++ b/Makefile
@@ -189,7 +189,12 @@ check-tenants: ## Vérifier que les tenants répondent
 # =============================================================================
 
 .PHONY: install
-install: up jwt-keys warmup ## Installation complète après clone
+install: up jwt-keys migrate warmup ## Installation complète après clone
+
+.PHONY: migrate
+migrate: ## Exécuter les migrations Doctrine
+	docker compose exec php php bin/console doctrine:database:create --if-not-exists
+	docker compose exec php php bin/console doctrine:migrations:migrate --no-interaction
 
 .PHONY: jwt-keys
 jwt-keys: ## Générer les clés JWT (requis après clone)
diff --git a/backend/config/packages/messenger.yaml b/backend/config/packages/messenger.yaml
index 722366e..cb54532 100644
--- a/backend/config/packages/messenger.yaml
+++ b/backend/config/packages/messenger.yaml
@@ -10,14 +10,22 @@ framework:
             command.bus:
                 default_middleware: true
                 middleware:
+                    - App\Shared\Infrastructure\Messenger\AddCorrelationIdStampMiddleware
+                    - App\Shared\Infrastructure\Messenger\CorrelationIdMiddleware
                     - doctrine_transaction
 
             query.bus:
                 default_middleware: true
+                middleware:
+                    - App\Shared\Infrastructure\Messenger\AddCorrelationIdStampMiddleware
+                    - App\Shared\Infrastructure\Messenger\CorrelationIdMiddleware
 
             event.bus:
                 default_middleware:
                     allow_no_handlers: true
+                middleware:
+                    - App\Shared\Infrastructure\Messenger\AddCorrelationIdStampMiddleware
+                    - App\Shared\Infrastructure\Messenger\CorrelationIdMiddleware
 
         transports:
             # https://symfony.com/doc/current/messenger.html#transport-configuration
diff --git a/backend/config/services.yaml b/backend/config/services.yaml
index e0f45b1..4662edf 100644
--- a/backend/config/services.yaml
+++ b/backend/config/services.yaml
@@ -91,10 +91,17 @@ services:
         arguments:
             $appUrl: '%app.url%'
 
-    # Audit log handler (uses dedicated audit channel)
-    App\Administration\Infrastructure\Messaging\AuditLoginEventsHandler:
+    # Audit Logger Service (writes to append-only audit_log table)
+    App\Shared\Application\Port\AuditLogger:
+        alias: App\Shared\Infrastructure\Audit\AuditLogger
+
+    App\Shared\Infrastructure\Audit\AuditLogger:
+        arguments:
+            $appSecret: '%env(APP_SECRET)%'
+
+    # Audit log handlers (use AuditLogger to write to database)
+    App\Shared\Infrastructure\Audit\Handler\AuditAuthenticationHandler:
         arguments:
-            $auditLogger: '@monolog.logger.audit'
             $appSecret: '%env(APP_SECRET)%'
 
     # JWT Authentication
diff --git a/backend/migrations/Version20260203100000.php b/backend/migrations/Version20260203100000.php
new file mode 100644
index 0000000..4bfe91f
--- /dev/null
+++ b/backend/migrations/Version20260203100000.php
@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+/**
+ * Migration pour la table audit_log append-only.
+ *
+ * @see Story 1.7 - T1: Schema Event Store
+ * @see FR90: Tracage actions sensibles
+ * @see NFR-S7: Audit trail immutable
+ */
+final class Version20260203100000 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Create audit_log table with append-only constraints (Story 1.7)';
+    }
+
+    public function up(Schema $schema): void
+    {
+        // T1.1 & T1.2: Create audit_log table
+        $this->addSql(<<<'SQL'
+            CREATE TABLE audit_log (
+                id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+                aggregate_type VARCHAR(255) NOT NULL,
+                aggregate_id UUID,
+                event_type VARCHAR(255) NOT NULL,
+                payload JSONB NOT NULL,
+                metadata JSONB NOT NULL,
+                occurred_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+                sequence_number BIGSERIAL NOT NULL
+            )
+        SQL);
+
+        // T1.4: Indexes for efficient querying
+        $this->addSql("CREATE INDEX idx_audit_tenant ON audit_log((metadata->>'tenant_id'))");
+        $this->addSql("CREATE INDEX idx_audit_user ON audit_log((metadata->>'user_id'))");
+        $this->addSql('CREATE INDEX idx_audit_occurred ON audit_log(occurred_at)');
+        $this->addSql('CREATE INDEX idx_audit_aggregate ON audit_log(aggregate_type, aggregate_id)');
+        $this->addSql("CREATE INDEX idx_audit_correlation ON audit_log((metadata->>'correlation_id'))");
+        $this->addSql('CREATE INDEX idx_audit_event_type ON audit_log(event_type)');
+
+        // T1.3: Append-only constraints - prevent UPDATE and DELETE
+        $this->addSql('CREATE RULE audit_no_update AS ON UPDATE TO audit_log DO INSTEAD NOTHING');
+        $this->addSql('CREATE RULE audit_no_delete AS ON DELETE TO audit_log DO INSTEAD NOTHING');
+
+        // Add comment to document the immutability constraint
+        $this->addSql("COMMENT ON TABLE audit_log IS 'Append-only audit log table. UPDATE and DELETE operations are disabled via PostgreSQL rules for immutability (NFR-S7).'");
+    }
+
+    public function down(Schema $schema): void
+    {
+        // Drop rules first
+        $this->addSql('DROP RULE IF EXISTS audit_no_update ON audit_log');
+        $this->addSql('DROP RULE IF EXISTS audit_no_delete ON audit_log');
+
+        // Drop table (indexes are dropped automatically)
+        $this->addSql('DROP TABLE IF EXISTS audit_log');
+    }
+}
diff --git a/backend/migrations/Version20260203100001.php b/backend/migrations/Version20260203100001.php
new file mode 100644
index 0000000..e6aaa9e
--- /dev/null
+++ b/backend/migrations/Version20260203100001.php
@@ -0,0 +1,118 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+/**
+ * Migration pour la table audit_log_archive et la fonction d'archivage.
+ *
+ * @see Story 1.7 - T8: Archivage
+ * @see NFR-C5: Duree conservation 5 ans actif, puis archive
+ */
+final class Version20260203100001 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Create audit_log_archive table and archival function (Story 1.7)';
+    }
+
+    public function up(Schema $schema): void
+    {
+        // T8.1: Create archive table with same structure as audit_log
+        $this->addSql(<<<'SQL'
+            CREATE TABLE audit_log_archive (
+                id UUID PRIMARY KEY,
+                aggregate_type VARCHAR(255) NOT NULL,
+                aggregate_id UUID,
+                event_type VARCHAR(255) NOT NULL,
+                payload JSONB NOT NULL,
+                metadata JSONB NOT NULL,
+                occurred_at TIMESTAMPTZ NOT NULL,
+                sequence_number BIGINT NOT NULL,
+                archived_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+            )
+        SQL);
+
+        // Indexes for archive queries (less aggressive than active table)
+        // Note: No event_type index on archive - less frequent queries, trade space for insert speed
+        $this->addSql("CREATE INDEX idx_audit_archive_tenant ON audit_log_archive((metadata->>'tenant_id'))");
+        $this->addSql('CREATE INDEX idx_audit_archive_occurred ON audit_log_archive(occurred_at)');
+        $this->addSql('CREATE INDEX idx_audit_archive_archived ON audit_log_archive(archived_at)');
+
+        // Archive is also append-only (immutable)
+        $this->addSql('CREATE RULE audit_archive_no_update AS ON UPDATE TO audit_log_archive DO INSTEAD NOTHING');
+        $this->addSql('CREATE RULE audit_archive_no_delete AS ON DELETE TO audit_log_archive DO INSTEAD NOTHING');
+
+        $this->addSql("COMMENT ON TABLE audit_log_archive IS 'Archived audit entries (>5 years old). Append-only, immutable. Entries are moved from audit_log, not copied.'");
+
+        // T8.2-T8.3: Create SECURITY DEFINER function to bypass audit_no_delete rule
+        // This is the ONLY way to delete from audit_log - for archival purposes only
+        $this->addSql(<<<'SQL'
+            CREATE OR REPLACE FUNCTION archive_audit_entries(
+                p_cutoff_date TIMESTAMPTZ,
+                p_batch_size INTEGER
+            )
+            RETURNS INTEGER
+            LANGUAGE plpgsql
+            SECURITY DEFINER
+            SET search_path = public
+            AS $$
+            DECLARE
+                v_archived_count INTEGER;
+                v_ids UUID[];
+            BEGIN
+                -- Select IDs to archive (oldest first, up to batch_size)
+                SELECT ARRAY_AGG(id ORDER BY sequence_number ASC)
+                INTO v_ids
+                FROM (
+                    SELECT id, sequence_number
+                    FROM audit_log
+                    WHERE occurred_at < p_cutoff_date
+                    ORDER BY sequence_number ASC
+                    LIMIT p_batch_size
+                ) sub;
+
+                -- Nothing to archive
+                IF v_ids IS NULL OR array_length(v_ids, 1) IS NULL THEN
+                    RETURN 0;
+                END IF;
+
+                -- Insert into archive
+                INSERT INTO audit_log_archive (
+                    id, aggregate_type, aggregate_id, event_type,
+                    payload, metadata, occurred_at, sequence_number
+                )
+                SELECT
+                    id, aggregate_type, aggregate_id, event_type,
+                    payload, metadata, occurred_at, sequence_number
+                FROM audit_log
+                WHERE id = ANY(v_ids);
+
+                GET DIAGNOSTICS v_archived_count = ROW_COUNT;
+
+                -- Delete from source table (bypasses rule via SECURITY DEFINER)
+                -- We temporarily disable the rule for this session
+                ALTER TABLE audit_log DISABLE RULE audit_no_delete;
+                DELETE FROM audit_log WHERE id = ANY(v_ids);
+                ALTER TABLE audit_log ENABLE RULE audit_no_delete;
+
+                RETURN v_archived_count;
+            END;
+            $$
+        SQL);
+
+        $this->addSql("COMMENT ON FUNCTION archive_audit_entries IS 'Moves audit entries older than cutoff to archive table. Only method to delete from audit_log. Requires superuser or table owner.'");
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('DROP FUNCTION IF EXISTS archive_audit_entries');
+        $this->addSql('DROP RULE IF EXISTS audit_archive_no_update ON audit_log_archive');
+        $this->addSql('DROP RULE IF EXISTS audit_archive_no_delete ON audit_log_archive');
+        $this->addSql('DROP TABLE IF EXISTS audit_log_archive');
+    }
+}
diff --git a/backend/src/Administration/Domain/Event/CompteBloqueTemporairement.php b/backend/src/Administration/Domain/Event/CompteBloqueTemporairement.php
index a46c9da..23b5ada 100644
--- a/backend/src/Administration/Domain/Event/CompteBloqueTemporairement.php
+++ b/backend/src/Administration/Domain/Event/CompteBloqueTemporairement.php
@@ -5,6 +5,7 @@ declare(strict_types=1);
 namespace App\Administration\Domain\Event;
 
 use App\Shared\Domain\DomainEvent;
+use App\Shared\Domain\Tenant\TenantId;
 use DateTimeImmutable;
 use Ramsey\Uuid\Uuid;
 use Ramsey\Uuid\UuidInterface;
@@ -20,6 +21,7 @@ final readonly class CompteBloqueTemporairement implements DomainEvent
 {
     public function __construct(
         public string $email,
+        public ?TenantId $tenantId,
         public string $ipAddress,
         public string $userAgent,
         public int $blockedForSeconds,
diff --git a/backend/src/Administration/Domain/Event/ConnexionEchouee.php b/backend/src/Administration/Domain/Event/ConnexionEchouee.php
index 0eaf991..13733b4 100644
--- a/backend/src/Administration/Domain/Event/ConnexionEchouee.php
+++ b/backend/src/Administration/Domain/Event/ConnexionEchouee.php
@@ -5,6 +5,7 @@ declare(strict_types=1);
 namespace App\Administration\Domain\Event;
 
 use App\Shared\Domain\DomainEvent;
+use App\Shared\Domain\Tenant\TenantId;
 use DateTimeImmutable;
 use Ramsey\Uuid\Uuid;
 use Ramsey\Uuid\UuidInterface;
@@ -21,6 +22,7 @@ final readonly class ConnexionEchouee implements DomainEvent
 {
     public function __construct(
         public string $email,
+        public ?TenantId $tenantId,
         public string $ipAddress,
         public string $userAgent,
         public string $reason, // 'invalid_credentials', 'account_locked', 'rate_limited'
diff --git a/backend/src/Administration/Infrastructure/Messaging/AuditLoginEventsHandler.php b/backend/src/Administration/Infrastructure/Messaging/AuditLoginEventsHandler.php
deleted file mode 100644
index 99f8aed..0000000
--- a/backend/src/Administration/Infrastructure/Messaging/AuditLoginEventsHandler.php
+++ /dev/null
@@ -1,76 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace App\Administration\Infrastructure\Messaging;
-
-use App\Administration\Domain\Event\ConnexionEchouee;
-use App\Administration\Domain\Event\ConnexionReussie;
-use Psr\Log\LoggerInterface;
-use Symfony\Component\Messenger\Attribute\AsMessageHandler;
-
-/**
- * Enregistre les événements de connexion dans l'audit log.
- *
- * Important: Les IP sont hashées pour respecter NFR-S3 (pas de PII dans les logs).
- *
- * @see Story 1.4 - T5.5: Tracer dans audit log
- * @see AC3: Événement tracé dans audit log
- */
-final readonly class AuditLoginEventsHandler
-{
-    public function __construct(
-        private LoggerInterface $auditLogger,
-        private string $appSecret,
-    ) {
-    }
-
-    #[AsMessageHandler]
-    public function handleConnexionReussie(ConnexionReussie $event): void
-    {
-        $this->auditLogger->info('login.success', [
-            'user_id' => $event->userId,
-            'tenant_id' => (string) $event->tenantId,
-            'ip_hash' => $this->hashIp($event->ipAddress),
-            'user_agent_hash' => $this->hashUserAgent($event->userAgent),
-            'occurred_on' => $event->occurredOn->format('c'),
-        ]);
-    }
-
-    #[AsMessageHandler]
-    public function handleConnexionEchouee(ConnexionEchouee $event): void
-    {
-        $this->auditLogger->warning('login.failure', [
-            'email_hash' => $this->hashEmail($event->email),
-            'reason' => $event->reason,
-            'ip_hash' => $this->hashIp($event->ipAddress),
-            'user_agent_hash' => $this->hashUserAgent($event->userAgent),
-            'occurred_on' => $event->occurredOn->format('c'),
-        ]);
-    }
-
-    /**
-     * Hash l'IP pour éviter de stocker des PII.
-     * Le hash permet toujours de corréler les événements d'une même IP.
-     */
-    private function hashIp(string $ip): string
-    {
-        return hash('sha256', $ip . $this->appSecret);
-    }
-
-    /**
-     * Hash l'email pour éviter de stocker des PII.
-     */
-    private function hashEmail(string $email): string
-    {
-        return hash('sha256', strtolower($email) . $this->appSecret);
-    }
-
-    /**
-     * Hash le User-Agent (généralement pas PII mais peut être très long).
-     */
-    private function hashUserAgent(string $userAgent): string
-    {
-        return hash('sha256', $userAgent);
-    }
-}
diff --git a/backend/src/Administration/Infrastructure/Security/LoginFailureHandler.php b/backend/src/Administration/Infrastructure/Security/LoginFailureHandler.php
index 00e8012..cddd254 100644
--- a/backend/src/Administration/Infrastructure/Security/LoginFailureHandler.php
+++ b/backend/src/Administration/Infrastructure/Security/LoginFailureHandler.php
@@ -7,8 +7,10 @@ namespace App\Administration\Infrastructure\Security;
 use App\Administration\Domain\Event\CompteBloqueTemporairement;
 use App\Administration\Domain\Event\ConnexionEchouee;
 use App\Shared\Domain\Clock;
+use App\Shared\Domain\Tenant\TenantId;
 use App\Shared\Infrastructure\RateLimit\LoginRateLimiterInterface;
 use App\Shared\Infrastructure\RateLimit\LoginRateLimitResult;
+use App\Shared\Infrastructure\Tenant\TenantResolver;
 
 use function is_array;
 use function is_string;
@@ -20,12 +22,16 @@ use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Messenger\MessageBusInterface;
 use Symfony\Component\Security\Core\Exception\AuthenticationException;
 use Symfony\Component\Security\Http\Authentication\AuthenticationFailureHandlerInterface;
+use Throwable;
 
 /**
  * Handles login failures: Fibonacci rate limiting, audit, user-friendly messages.
  *
  * Important: Never reveal whether the email exists or not (AC2).
  *
+ * Note: /api/login is excluded from TenantMiddleware, so we resolve tenant
+ * directly from host header using TenantResolver.
+ *
  * @see Story 1.4 - T5: Backend Login Endpoint
  */
 final readonly class LoginFailureHandler implements AuthenticationFailureHandlerInterface
@@ -34,6 +40,7 @@ final readonly class LoginFailureHandler implements AuthenticationFailureHandler
         private LoginRateLimiterInterface $rateLimiter,
         private MessageBusInterface $eventBus,
         private Clock $clock,
+        private TenantResolver $tenantResolver,
     ) {
     }
 
@@ -49,9 +56,12 @@ final readonly class LoginFailureHandler implements AuthenticationFailureHandler
         // Record the failure and get the new state
         $result = $this->rateLimiter->recordFailure($request, $email);
 
-        // Dispatch the failure event
+        // Resolve tenant from host header (TenantMiddleware skips /api/login)
+        $tenantId = $this->resolveTenantFromHost($request);
+
         $this->eventBus->dispatch(new ConnexionEchouee(
             email: $email,
+            tenantId: $tenantId,
             ipAddress: $ipAddress,
             userAgent: $userAgent,
             reason: 'invalid_credentials',
@@ -62,6 +72,7 @@ final readonly class LoginFailureHandler implements AuthenticationFailureHandler
         if ($result->ipBlocked) {
             $this->eventBus->dispatch(new CompteBloqueTemporairement(
                 email: $email,
+                tenantId: $tenantId,
                 ipAddress: $ipAddress,
                 userAgent: $userAgent,
                 blockedForSeconds: $result->retryAfter ?? LoginRateLimiterInterface::IP_BLOCK_DURATION,
@@ -125,4 +136,26 @@ final readonly class LoginFailureHandler implements AuthenticationFailureHandler
 
         return $response;
     }
+
+    /**
+     * Resolve tenant from request host header.
+     *
+     * Since /api/login is excluded from TenantMiddleware, we must resolve
+     * the tenant ourselves to properly scope audit events.
+     *
+     * Returns null if tenant cannot be resolved (unknown domain, database issues, etc.)
+     * to ensure login failure handling never breaks due to tenant resolution.
+     */
+    private function resolveTenantFromHost(Request $request): ?TenantId
+    {
+        try {
+            $config = $this->tenantResolver->resolve($request->getHost());
+
+            return $config->tenantId;
+        } catch (Throwable) {
+            // Login attempt on unknown domain or tenant resolution failed
+            // Don't let tenant resolution break the login failure handling
+            return null;
+        }
+    }
 }
diff --git a/backend/src/Shared/Application/Port/AuditLogger.php b/backend/src/Shared/Application/Port/AuditLogger.php
new file mode 100644
index 0000000..8d083a3
--- /dev/null
+++ b/backend/src/Shared/Application/Port/AuditLogger.php
@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Shared\Application\Port;
+
+use Ramsey\Uuid\UuidInterface;
+
+/**
+ * Port for audit logging.
+ *
+ * Infrastructure implementation writes to append-only database table.
+ *
+ * @see Story 1.7 - T2: AuditLogger Service
+ */
+interface AuditLogger
+{
+    /**
+     * Log authentication events (login success/failure, account blocked, etc.).
+     *
+     * @param array<string, mixed> $payload  Event-specific data
+     * @param string|null          $tenantId Override tenant from event (for async handlers without TenantContext)
+     */
+    public function logAuthentication(
+        string $eventType,
+        ?UuidInterface $userId,
+        array $payload,
+        ?string $tenantId = null,
+    ): void;
+
+    /**
+     * Log data changes (notes, absences, student data modifications).
+     *
+     * @param array<string, mixed> $oldValues Previous values
+     * @param array<string, mixed> $newValues New values
+     */
+    public function logDataChange(
+        string $aggregateType,
+        UuidInterface $aggregateId,
+        string $eventType,
+        array $oldValues,
+        array $newValues,
+        ?string $reason = null,
+    ): void;
+
+    /**
+     * Log export operations (CSV, PDF, RGPD data exports).
+     */
+    public function logExport(
+        string $exportType,
+        int $recordCount,
+        ?string $targetDescription = null,
+    ): void;
+
+    /**
+     * Log access to sensitive data (student records, etc.).
+     *
+     * @param array<string, mixed> $context Additional context (screen, action)
+     */
+    public function logAccess(
+        string $resourceType,
+        UuidInterface $resourceId,
+        array $context = [],
+    ): void;
+}
diff --git a/backend/src/Shared/Domain/CorrelationId.php b/backend/src/Shared/Domain/CorrelationId.php
index 08d0fc0..e500ca8 100644
--- a/backend/src/Shared/Domain/CorrelationId.php
+++ b/backend/src/Shared/Domain/CorrelationId.php
@@ -4,8 +4,11 @@ declare(strict_types=1);
 
 namespace App\Shared\Domain;
 
+use InvalidArgumentException;
 use Ramsey\Uuid\Uuid;
 
+use function sprintf;
+
 final readonly class CorrelationId
 {
     private function __construct(
@@ -20,6 +23,12 @@ final readonly class CorrelationId
 
     public static function fromString(string $value): self
     {
+        if (!Uuid::isValid($value)) {
+            throw new InvalidArgumentException(
+                sprintf('Invalid correlation ID format: "%s". Expected UUID.', $value),
+            );
+        }
+
         return new self($value);
     }
 
diff --git a/backend/src/Shared/Infrastructure/Audit/AuditLogEntry.php b/backend/src/Shared/Infrastructure/Audit/AuditLogEntry.php
new file mode 100644
index 0000000..675f2d9
--- /dev/null
+++ b/backend/src/Shared/Infrastructure/Audit/AuditLogEntry.php
@@ -0,0 +1,101 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Shared\Infrastructure\Audit;
+
+use DateTimeImmutable;
+
+use const JSON_THROW_ON_ERROR;
+
+use Ramsey\Uuid\Uuid;
+use Ramsey\Uuid\UuidInterface;
+
+/**
+ * Read model for audit log entries.
+ *
+ * Immutable DTO representing a single audit log entry.
+ */
+final readonly class AuditLogEntry
+{
+    /**
+     * @param array<string, mixed> $payload
+     * @param array<string, mixed> $metadata
+     */
+    public function __construct(
+        public UuidInterface $id,
+        public string $aggregateType,
+        public ?UuidInterface $aggregateId,
+        public string $eventType,
+        public array $payload,
+        public array $metadata,
+        public DateTimeImmutable $occurredAt,
+        public int $sequenceNumber,
+    ) {
+    }
+
+    /**
+     * @param array<string, mixed> $row
+     */
+    public static function fromDatabaseRow(array $row): self
+    {
+        /** @var string $id */
+        $id = $row['id'];
+        /** @var string $aggregateType */
+        $aggregateType = $row['aggregate_type'];
+        /** @var string|null $aggregateId */
+        $aggregateId = $row['aggregate_id'];
+        /** @var string $eventType */
+        $eventType = $row['event_type'];
+        /** @var string $payloadJson */
+        $payloadJson = $row['payload'];
+        /** @var string $metadataJson */
+        $metadataJson = $row['metadata'];
+        /** @var string $occurredAt */
+        $occurredAt = $row['occurred_at'];
+        /** @var string|int $sequenceNumber */
+        $sequenceNumber = $row['sequence_number'];
+
+        /** @var array<string, mixed> $payload */
+        $payload = json_decode($payloadJson, true, 512, JSON_THROW_ON_ERROR);
+        /** @var array<string, mixed> $metadata */
+        $metadata = json_decode($metadataJson, true, 512, JSON_THROW_ON_ERROR);
+
+        return new self(
+            id: Uuid::fromString($id),
+            aggregateType: $aggregateType,
+            aggregateId: $aggregateId !== null
+                ? Uuid::fromString($aggregateId)
+                : null,
+            eventType: $eventType,
+            payload: $payload,
+            metadata: $metadata,
+            occurredAt: new DateTimeImmutable($occurredAt),
+            sequenceNumber: (int) $sequenceNumber,
+        );
+    }
+
+    public function correlationId(): ?string
+    {
+        /** @var string|null $correlationId */
+        $correlationId = $this->metadata['correlation_id'] ?? null;
+
+        return $correlationId;
+    }
+
+    public function tenantId(): ?string
+    {
+        /** @var string|null $tenantId */
+        $tenantId = $this->metadata['tenant_id'] ?? null;
+
+        return $tenantId;
+    }
+
+    public function userId(): ?string
+    {
+        /** @var string|null $userId */
+        $userId = $this->metadata['user_id'] ?? null;
+
+        return $userId;
+    }
+}
diff --git a/backend/src/Shared/Infrastructure/Audit/AuditLogRepository.php b/backend/src/Shared/Infrastructure/Audit/AuditLogRepository.php
new file mode 100644
index 0000000..71a938f
--- /dev/null
+++ b/backend/src/Shared/Infrastructure/Audit/AuditLogRepository.php
@@ -0,0 +1,188 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Shared\Infrastructure\Audit;
+
+use App\Shared\Domain\Tenant\TenantId;
+use DateTimeImmutable;
+use Doctrine\DBAL\Connection;
+use Ramsey\Uuid\UuidInterface;
+
+/**
+ * Repository for querying audit logs.
+ *
+ * Provides investigation queries for administrators and DPOs.
+ * All queries are tenant-scoped for security.
+ *
+ * @see Story 1.7 - T9: Requetes d'investigation
+ */
+final readonly class AuditLogRepository
+{
+    public function __construct(
+        private Connection $connection,
+    ) {
+    }
+
+    /**
+     * Get audit logs for a specific user.
+     *
+     * @see T9.1: Query GetAuditLogByUser
+     *
+     * @return list<AuditLogEntry>
+     */
+    public function findByUser(
+        UuidInterface $userId,
+        TenantId $tenantId,
+        ?DateTimeImmutable $from = null,
+        ?DateTimeImmutable $to = null,
+        ?string $eventType = null,
+        int $limit = 100,
+        int $offset = 0,
+    ): array {
+        $qb = $this->connection->createQueryBuilder()
+            ->select('*')
+            ->from('audit_log')
+            ->where("metadata->>'user_id' = :user_id")
+            ->andWhere("metadata->>'tenant_id' = :tenant_id")
+            ->setParameter('user_id', $userId->toString())
+            ->setParameter('tenant_id', (string) $tenantId)
+            ->orderBy('occurred_at', 'DESC')
+            ->setMaxResults($limit)
+            ->setFirstResult($offset);
+
+        $this->applyFilters($qb, $from, $to, $eventType);
+
+        return $this->mapResults($qb->executeQuery()->fetchAllAssociative());
+    }
+
+    /**
+     * Get audit logs for a specific resource (aggregate).
+     *
+     * @see T9.2: Query GetAuditLogByResource
+     *
+     * @return list<AuditLogEntry>
+     */
+    public function findByResource(
+        string $aggregateType,
+        UuidInterface $aggregateId,
+        TenantId $tenantId,
+        ?DateTimeImmutable $from = null,
+        ?DateTimeImmutable $to = null,
+        int $limit = 100,
+        int $offset = 0,
+    ): array {
+        $qb = $this->connection->createQueryBuilder()
+            ->select('*')
+            ->from('audit_log')
+            ->where('aggregate_type = :aggregate_type')
+            ->andWhere('aggregate_id = :aggregate_id')
+            ->andWhere("metadata->>'tenant_id' = :tenant_id")
+            ->setParameter('aggregate_type', $aggregateType)
+            ->setParameter('aggregate_id', $aggregateId->toString())
+            ->setParameter('tenant_id', (string) $tenantId)
+            ->orderBy('occurred_at', 'DESC')
+            ->setMaxResults($limit)
+            ->setFirstResult($offset);
+
+        $this->applyFilters($qb, $from, $to, null);
+
+        return $this->mapResults($qb->executeQuery()->fetchAllAssociative());
+    }
+
+    /**
+     * Get audit logs by correlation ID (trace a full request).
+     *
+     * @see T9.3: Query GetAuditLogByCorrelationId
+     *
+     * @return list<AuditLogEntry>
+     */
+    public function findByCorrelationId(
+        string $correlationId,
+        TenantId $tenantId,
+    ): array {
+        $qb = $this->connection->createQueryBuilder()
+            ->select('*')
+            ->from('audit_log')
+            ->where("metadata->>'correlation_id' = :correlation_id")
+            ->andWhere("metadata->>'tenant_id' = :tenant_id")
+            ->setParameter('correlation_id', $correlationId)
+            ->setParameter('tenant_id', (string) $tenantId)
+            ->orderBy('occurred_at', 'ASC');
+
+        return $this->mapResults($qb->executeQuery()->fetchAllAssociative());
+    }
+
+    /**
+     * Search audit logs with multiple filters.
+     *
+     * @see T9.4: Filtres avances
+     *
+     * @return list<AuditLogEntry>
+     */
+    public function search(
+        TenantId $tenantId,
+        ?DateTimeImmutable $from = null,
+        ?DateTimeImmutable $to = null,
+        ?string $eventType = null,
+        ?string $aggregateType = null,
+        int $limit = 100,
+        int $offset = 0,
+    ): array {
+        $qb = $this->connection->createQueryBuilder()
+            ->select('*')
+            ->from('audit_log')
+            ->where("metadata->>'tenant_id' = :tenant_id")
+            ->setParameter('tenant_id', (string) $tenantId)
+            ->orderBy('occurred_at', 'DESC')
+            ->setMaxResults($limit)
+            ->setFirstResult($offset);
+
+        $this->applyFilters($qb, $from, $to, $eventType);
+
+        if ($aggregateType !== null) {
+            $qb->andWhere('aggregate_type = :aggregate_type')
+                ->setParameter('aggregate_type', $aggregateType);
+        }
+
+        return $this->mapResults($qb->executeQuery()->fetchAllAssociative());
+    }
+
+    /**
+     * @param \Doctrine\DBAL\Query\QueryBuilder $qb
+     */
+    private function applyFilters(
+        $qb,
+        ?DateTimeImmutable $from,
+        ?DateTimeImmutable $to,
+        ?string $eventType,
+    ): void {
+        if ($from !== null) {
+            $qb->andWhere('occurred_at >= :from')
+                ->setParameter('from', $from->format('Y-m-d H:i:s.uP'));
+        }
+
+        if ($to !== null) {
+            $qb->andWhere('occurred_at <= :to')
+                ->setParameter('to', $to->format('Y-m-d H:i:s.uP'));
+        }
+
+        if ($eventType !== null) {
+            $qb->andWhere('event_type = :event_type')
+                ->setParameter('event_type', $eventType);
+        }
+    }
+
+    /**
+     * @param list<array<string, mixed>> $rows
+     *
+     * @return list<AuditLogEntry>
+     */
+    private function mapResults(array $rows): array
+    {
+        return array_map(
+            static fn (array $row): AuditLogEntry => AuditLogEntry::fromDatabaseRow($row),
+            $rows,
+        );
+    }
+}
diff --git a/backend/src/Shared/Infrastructure/Audit/AuditLogger.php b/backend/src/Shared/Infrastructure/Audit/AuditLogger.php
new file mode 100644
index 0000000..6907664
--- /dev/null
+++ b/backend/src/Shared/Infrastructure/Audit/AuditLogger.php
@@ -0,0 +1,215 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Shared\Infrastructure\Audit;
+
+use App\Shared\Application\Port\AuditLogger as AuditLoggerInterface;
+use App\Shared\Domain\Clock;
+use App\Shared\Infrastructure\Tenant\TenantContext;
+use Doctrine\DBAL\Connection;
+use Override;
+use Ramsey\Uuid\UuidInterface;
+use Symfony\Component\HttpFoundation\RequestStack;
+use Symfony\Component\Security\Core\Authentication\Token\Storage\TokenStorageInterface;
+
+/**
+ * Centralized audit logging service.
+ *
+ * All sensitive actions are logged to the append-only audit_log table.
+ * Metadata (tenant, user, IP, correlation_id) is automatically injected.
+ *
+ * IMPORTANT: No PII in logs (NFR-S3). IPs/emails are hashed.
+ *
+ * @see Story 1.7 - T2: AuditLogger Service
+ * @see FR90: Tracage actions sensibles
+ * @see NFR-S3: Pas de PII dans les logs
+ * @see NFR-S7: Audit trail immutable
+ */
+final readonly class AuditLogger implements AuditLoggerInterface
+{
+    public function __construct(
+        private Connection $connection,
+        private TenantContext $tenantContext,
+        private TokenStorageInterface $tokenStorage,
+        private RequestStack $requestStack,
+        private Clock $clock,
+        private string $appSecret,
+    ) {
+    }
+
+    #[Override]
+    public function logAuthentication(
+        string $eventType,
+        ?UuidInterface $userId,
+        array $payload,
+        ?string $tenantId = null,
+    ): void {
+        $this->log(
+            aggregateType: 'User',
+            aggregateId: $userId,
+            eventType: $eventType,
+            payload: $payload,
+            tenantIdOverride: $tenantId,
+            userIdOverride: $userId?->toString(),
+        );
+    }
+
+    #[Override]
+    public function logDataChange(
+        string $aggregateType,
+        UuidInterface $aggregateId,
+        string $eventType,
+        array $oldValues,
+        array $newValues,
+        ?string $reason = null,
+    ): void {
+        $payload = [
+            'old_values' => $oldValues,
+            'new_values' => $newValues,
+        ];
+
+        if ($reason !== null) {
+            $payload['reason'] = $reason;
+        }
+
+        $this->log(
+            aggregateType: $aggregateType,
+            aggregateId: $aggregateId,
+            eventType: $eventType,
+            payload: $payload,
+        );
+    }
+
+    #[Override]
+    public function logExport(
+        string $exportType,
+        int $recordCount,
+        ?string $targetDescription = null,
+    ): void {
+        $payload = [
+            'export_type' => $exportType,
+            'record_count' => $recordCount,
+        ];
+
+        if ($targetDescription !== null) {
+            $payload['target'] = $targetDescription;
+        }
+
+        $this->log(
+            aggregateType: 'Export',
+            aggregateId: null,
+            eventType: 'ExportGenerated',
+            payload: $payload,
+        );
+    }
+
+    #[Override]
+    public function logAccess(
+        string $resourceType,
+        UuidInterface $resourceId,
+        array $context = [],
+    ): void {
+        $this->log(
+            aggregateType: $resourceType,
+            aggregateId: $resourceId,
+            eventType: 'ResourceAccessed',
+            payload: $context,
+        );
+    }
+
+    /**
+     * Core logging method - writes to append-only audit_log table.
+     *
+     * @param array<string, mixed> $payload          Event-specific data
+     * @param string|null          $tenantIdOverride Override tenant (for async handlers without TenantContext)
+     * @param string|null          $userIdOverride   Override user (for async handlers without security token)
+     */
+    private function log(
+        string $aggregateType,
+        ?UuidInterface $aggregateId,
+        string $eventType,
+        array $payload,
+        ?string $tenantIdOverride = null,
+        ?string $userIdOverride = null,
+    ): void {
+        $metadata = $this->buildMetadata($tenantIdOverride, $userIdOverride);
+
+        // Pass raw arrays - DBAL handles JSON encoding with 'json' type binding
+        $this->connection->insert('audit_log', [
+            'aggregate_type' => $aggregateType,
+            'aggregate_id' => $aggregateId?->toString(),
+            'event_type' => $eventType,
+            'payload' => $payload,
+            'metadata' => $metadata,
+            'occurred_at' => $this->clock->now()->format('Y-m-d H:i:s.uP'),
+        ], [
+            'payload' => 'json',
+            'metadata' => 'json',
+        ]);
+    }
+
+    /**
+     * Build metadata with automatic context injection.
+     *
+     * @param string|null $tenantIdOverride Override tenant from event (for async handlers)
+     * @param string|null $userIdOverride   Override user from event (for async handlers)
+     *
+     * @return array<string, string|null>
+     */
+    private function buildMetadata(?string $tenantIdOverride = null, ?string $userIdOverride = null): array
+    {
+        $request = $this->requestStack->getCurrentRequest();
+
+        $metadata = [
+            'correlation_id' => CorrelationIdHolder::getOrGenerate()->value(),
+            'occurred_at' => $this->clock->now()->format('c'),
+        ];
+
+        // Tenant ID: use override if provided, otherwise try TenantContext
+        // Override is needed for async handlers that don't have request context
+        if ($tenantIdOverride !== null) {
+            $metadata['tenant_id'] = $tenantIdOverride;
+        } elseif ($this->tenantContext->hasTenant()) {
+            $metadata['tenant_id'] = (string) $this->tenantContext->getCurrentTenantId();
+        }
+
+        // User ID: use override if provided, otherwise try security token
+        // Override is needed for async handlers that don't have security context
+        if ($userIdOverride !== null) {
+            $metadata['user_id'] = $userIdOverride;
+        } else {
+            $token = $this->tokenStorage->getToken();
+            if ($token !== null) {
+                $user = $token->getUser();
+                if ($user !== null && method_exists($user, 'userId')) {
+                    $metadata['user_id'] = $user->userId();
+                }
+            }
+        }
+
+        // IP and User-Agent (hashed for privacy)
+        if ($request !== null) {
+            $ip = $request->getClientIp();
+            if ($ip !== null) {
+                $metadata['ip_hash'] = $this->hashValue($ip);
+            }
+
+            $userAgent = $request->headers->get('User-Agent');
+            if ($userAgent !== null) {
+                $metadata['user_agent_hash'] = hash('sha256', $userAgent);
+            }
+        }
+
+        return $metadata;
+    }
+
+    /**
+     * Hash sensitive values (IP, email) using app secret.
+     * Allows correlation without storing PII.
+     */
+    private function hashValue(string $value): string
+    {
+        return hash('sha256', $value . $this->appSecret);
+    }
+}
diff --git a/backend/src/Shared/Infrastructure/Audit/CorrelationIdHolder.php b/backend/src/Shared/Infrastructure/Audit/CorrelationIdHolder.php
new file mode 100644
index 0000000..3dd1f42
--- /dev/null
+++ b/backend/src/Shared/Infrastructure/Audit/CorrelationIdHolder.php
@@ -0,0 +1,62 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Shared\Infrastructure\Audit;
+
+use App\Shared\Domain\CorrelationId;
+
+/**
+ * Thread-local storage for correlation ID.
+ *
+ * Allows any part of the application to access the current request's
+ * correlation ID for audit logging and distributed tracing.
+ *
+ * For HTTP requests, the CorrelationIdMiddleware sets the ID.
+ * For async handlers and CRON jobs, getOrGenerate() auto-creates one.
+ *
+ * NOTE: Static methods are used here because PHP lacks native thread-local
+ * storage (unlike Java's ThreadLocal). This is an accepted exception to the
+ * "no static" rule - see project-context.md "Nuance PHP 8.5 sur No Static".
+ *
+ * @see Story 1.7 - T3: Correlation ID
+ */
+final class CorrelationIdHolder
+{
+    private static ?CorrelationId $correlationId = null;
+
+    public static function set(CorrelationId $correlationId): void
+    {
+        self::$correlationId = $correlationId;
+    }
+
+    /**
+     * Get current correlation ID, or null if not set.
+     *
+     * Use getOrGenerate() when you need a correlation ID guaranteed.
+     */
+    public static function get(): ?CorrelationId
+    {
+        return self::$correlationId;
+    }
+
+    /**
+     * Get current correlation ID, or generate one if not set.
+     *
+     * Use this in contexts without HTTP request (async handlers, CRON jobs)
+     * to ensure traceability is never broken.
+     */
+    public static function getOrGenerate(): CorrelationId
+    {
+        if (self::$correlationId === null) {
+            self::$correlationId = CorrelationId::generate();
+        }
+
+        return self::$correlationId;
+    }
+
+    public static function clear(): void
+    {
+        self::$correlationId = null;
+    }
+}
diff --git a/backend/src/Shared/Infrastructure/Audit/Handler/AuditAuthenticationHandler.php b/backend/src/Shared/Infrastructure/Audit/Handler/AuditAuthenticationHandler.php
new file mode 100644
index 0000000..eb0e6cd
--- /dev/null
+++ b/backend/src/Shared/Infrastructure/Audit/Handler/AuditAuthenticationHandler.php
@@ -0,0 +1,106 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Shared\Infrastructure\Audit\Handler;
+
+use App\Administration\Domain\Event\CompteBloqueTemporairement;
+use App\Administration\Domain\Event\ConnexionEchouee;
+use App\Administration\Domain\Event\ConnexionReussie;
+use App\Administration\Domain\Event\MotDePasseChange;
+use App\Shared\Application\Port\AuditLogger;
+use Ramsey\Uuid\Uuid;
+use Symfony\Component\Messenger\Attribute\AsMessageHandler;
+
+/**
+ * Handles authentication events for audit logging.
+ *
+ * Writes to append-only audit_log table via AuditLogger.
+ * All PII (emails, IPs) are hashed before storage.
+ *
+ * @see Story 1.7 - T4: Listeners Authentification
+ * @see AC1: Tracage authentification
+ */
+final readonly class AuditAuthenticationHandler
+{
+    public function __construct(
+        private AuditLogger $auditLogger,
+        private string $appSecret,
+    ) {
+    }
+
+    /**
+     * T4.1: Successful login.
+     */
+    #[AsMessageHandler]
+    public function handleConnexionReussie(ConnexionReussie $event): void
+    {
+        $this->auditLogger->logAuthentication(
+            eventType: 'ConnexionReussie',
+            userId: Uuid::fromString($event->userId),
+            payload: [
+                'email_hash' => $this->hashEmail($event->email),
+                'result' => 'success',
+                'method' => 'password',
+            ],
+            tenantId: (string) $event->tenantId,
+        );
+    }
+
+    /**
+     * T4.2: Failed login.
+     */
+    #[AsMessageHandler]
+    public function handleConnexionEchouee(ConnexionEchouee $event): void
+    {
+        $this->auditLogger->logAuthentication(
+            eventType: 'ConnexionEchouee',
+            userId: null, // No user ID for failed logins
+            payload: [
+                'email_hash' => $this->hashEmail($event->email),
+                'result' => 'failure',
+                'reason' => $event->reason,
+            ],
+            tenantId: $event->tenantId !== null ? (string) $event->tenantId : null,
+        );
+    }
+
+    /**
+     * T4.3: Account temporarily locked.
+     */
+    #[AsMessageHandler]
+    public function handleCompteBloqueTemporairement(CompteBloqueTemporairement $event): void
+    {
+        $this->auditLogger->logAuthentication(
+            eventType: 'CompteBloqueTemporairement',
+            userId: null, // No user ID - we only have email
+            payload: [
+                'email_hash' => $this->hashEmail($event->email),
+                'blocked_for_seconds' => $event->blockedForSeconds,
+                'failed_attempts' => $event->failedAttempts,
+            ],
+            tenantId: $event->tenantId !== null ? (string) $event->tenantId : null,
+        );
+    }
+
+    /**
+     * T4.4: Password changed (via reset or update).
+     */
+    #[AsMessageHandler]
+    public function handleMotDePasseChange(MotDePasseChange $event): void
+    {
+        $this->auditLogger->logAuthentication(
+            eventType: 'MotDePasseChange',
+            userId: Uuid::fromString($event->userId),
+            payload: [
+                'email_hash' => $this->hashEmail($event->email),
+            ],
+            tenantId: (string) $event->tenantId,
+        );
+    }
+
+    private function hashEmail(string $email): string
+    {
+        return hash('sha256', strtolower($email) . $this->appSecret);
+    }
+}
diff --git a/backend/src/Shared/Infrastructure/Console/ArchiveAuditLogsCommand.php b/backend/src/Shared/Infrastructure/Console/ArchiveAuditLogsCommand.php
new file mode 100644
index 0000000..01c039c
--- /dev/null
+++ b/backend/src/Shared/Infrastructure/Console/ArchiveAuditLogsCommand.php
@@ -0,0 +1,181 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Shared\Infrastructure\Console;
+
+use App\Shared\Domain\Clock;
+use DateTimeImmutable;
+use Doctrine\DBAL\Connection;
+use Override;
+
+use function sprintf;
+
+use Symfony\Component\Console\Attribute\AsCommand;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Style\SymfonyStyle;
+
+/**
+ * Archives audit log entries older than 5 years.
+ *
+ * Entries are MOVED (not copied) to audit_log_archive table.
+ * This preserves immutability while managing table size.
+ *
+ * WARNING: This command temporarily disables PostgreSQL rules via ALTER TABLE,
+ * which acquires an AccessExclusiveLock. Schedule during LOW TRAFFIC periods only.
+ *
+ * Run via CRON: 0 2 * * 0 php bin/console app:audit:archive
+ *
+ * @see Story 1.7 - T8: Archivage
+ * @see NFR-C5: Conservation 5 ans actif, puis archive
+ */
+#[AsCommand(
+    name: 'app:audit:archive',
+    description: 'Archive audit log entries older than 5 years',
+)]
+final class ArchiveAuditLogsCommand extends Command
+{
+    private const int DEFAULT_RETENTION_YEARS = 5;
+    private const int DEFAULT_BATCH_SIZE = 1000;
+
+    public function __construct(
+        private readonly Connection $connection,
+        private readonly Clock $clock,
+    ) {
+        parent::__construct();
+    }
+
+    #[Override]
+    protected function configure(): void
+    {
+        $this
+            ->addOption(
+                'retention-years',
+                'r',
+                InputOption::VALUE_REQUIRED,
+                'Number of years to keep in active table',
+                (string) self::DEFAULT_RETENTION_YEARS,
+            )
+            ->addOption(
+                'batch-size',
+                'b',
+                InputOption::VALUE_REQUIRED,
+                'Number of records to process per batch',
+                (string) self::DEFAULT_BATCH_SIZE,
+            )
+            ->addOption(
+                'dry-run',
+                null,
+                InputOption::VALUE_NONE,
+                'Simulate without making changes',
+            );
+    }
+
+    #[Override]
+    protected function execute(InputInterface $input, OutputInterface $output): int
+    {
+        $io = new SymfonyStyle($input, $output);
+
+        /** @var string $retentionYearsOption */
+        $retentionYearsOption = $input->getOption('retention-years');
+        $retentionYears = (int) $retentionYearsOption;
+
+        if ($retentionYears < 1) {
+            $io->error('Retention years must be a positive integer.');
+
+            return Command::FAILURE;
+        }
+
+        /** @var string $batchSizeOption */
+        $batchSizeOption = $input->getOption('batch-size');
+        $batchSize = (int) $batchSizeOption;
+
+        if ($batchSize < 1) {
+            $io->error('Batch size must be a positive integer.');
+
+            return Command::FAILURE;
+        }
+
+        $dryRun = (bool) $input->getOption('dry-run');
+
+        $cutoffDate = $this->clock->now()->modify("-{$retentionYears} years");
+        $io->title('Audit Log Archival');
+        $io->info(sprintf(
+            'Archiving entries older than %s (%d years retention)',
+            $cutoffDate->format('Y-m-d H:i:s'),
+            $retentionYears,
+        ));
+
+        if ($dryRun) {
+            $io->warning('DRY RUN MODE - No changes will be made');
+        }
+
+        // Count entries to archive
+        $countSql = 'SELECT COUNT(*) FROM audit_log WHERE occurred_at < :cutoff';
+        /** @var string|int|false $countResult */
+        $countResult = $this->connection->fetchOne($countSql, [
+            'cutoff' => $cutoffDate->format('Y-m-d H:i:s.uP'),
+        ]);
+        $totalCount = (int) $countResult;
+
+        if ($totalCount === 0) {
+            $io->success('No entries to archive.');
+
+            return Command::SUCCESS;
+        }
+
+        $io->info(sprintf('Found %d entries to archive', $totalCount));
+
+        if ($dryRun) {
+            $io->success(sprintf('DRY RUN: Would archive %d entries', $totalCount));
+
+            return Command::SUCCESS;
+        }
+
+        // Archive in batches
+        $progressBar = $io->createProgressBar($totalCount);
+        $progressBar->start();
+        $archivedCount = 0;
+
+        do {
+            $batchCount = $this->archiveBatch($cutoffDate, $batchSize);
+            $archivedCount += $batchCount;
+            $progressBar->advance($batchCount);
+        } while ($batchCount === $batchSize);
+
+        $progressBar->finish();
+        $io->newLine(2);
+
+        $io->success(sprintf(
+            'Successfully archived %d audit log entries',
+            $archivedCount,
+        ));
+
+        return Command::SUCCESS;
+    }
+
+    /**
+     * Archive a batch of entries using PostgreSQL function.
+     *
+     * The archive_audit_entries() function is SECURITY DEFINER and can
+     * bypass the audit_no_delete rule. This is the ONLY way to delete
+     * from audit_log - ensuring immutability for normal operations.
+     */
+    private function archiveBatch(DateTimeImmutable $cutoffDate, int $batchSize): int
+    {
+        // Call the PostgreSQL function that handles INSERT + DELETE atomically
+        // The function uses SECURITY DEFINER to bypass the delete rule
+        $sql = 'SELECT archive_audit_entries(:cutoff, :batch_size)';
+
+        /** @var int|string|false $result */
+        $result = $this->connection->fetchOne($sql, [
+            'cutoff' => $cutoffDate->format('Y-m-d H:i:s.uP'),
+            'batch_size' => $batchSize,
+        ]);
+
+        return (int) $result;
+    }
+}
diff --git a/backend/src/Shared/Infrastructure/Messenger/AddCorrelationIdStampMiddleware.php b/backend/src/Shared/Infrastructure/Messenger/AddCorrelationIdStampMiddleware.php
new file mode 100644
index 0000000..838b12d
--- /dev/null
+++ b/backend/src/Shared/Infrastructure/Messenger/AddCorrelationIdStampMiddleware.php
@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Shared\Infrastructure\Messenger;
+
+use App\Shared\Infrastructure\Audit\CorrelationIdHolder;
+use Symfony\Component\Messenger\Envelope;
+use Symfony\Component\Messenger\Middleware\MiddlewareInterface;
+use Symfony\Component\Messenger\Middleware\StackInterface;
+
+/**
+ * Adds correlation ID stamp to outgoing messages.
+ *
+ * When a message is dispatched during an HTTP request, this middleware
+ * captures the current correlation ID and attaches it as a stamp.
+ * The receiving worker will then use this stamp to restore the correlation ID.
+ *
+ * @see Story 1.7 - T3: Correlation ID
+ */
+final readonly class AddCorrelationIdStampMiddleware implements MiddlewareInterface
+{
+    public function handle(Envelope $envelope, StackInterface $stack): Envelope
+    {
+        // Only add stamp if not already present and we have a correlation ID
+        if ($envelope->last(CorrelationIdStamp::class) === null) {
+            $correlationId = CorrelationIdHolder::get();
+            if ($correlationId !== null) {
+                $envelope = $envelope->with(new CorrelationIdStamp($correlationId->value()));
+            }
+        }
+
+        return $stack->next()->handle($envelope, $stack);
+    }
+}
diff --git a/backend/src/Shared/Infrastructure/Messenger/CorrelationIdMiddleware.php b/backend/src/Shared/Infrastructure/Messenger/CorrelationIdMiddleware.php
new file mode 100644
index 0000000..3988df7
--- /dev/null
+++ b/backend/src/Shared/Infrastructure/Messenger/CorrelationIdMiddleware.php
@@ -0,0 +1,60 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Shared\Infrastructure\Messenger;
+
+use App\Shared\Domain\CorrelationId;
+use App\Shared\Infrastructure\Audit\CorrelationIdHolder;
+use Symfony\Component\Messenger\Envelope;
+use Symfony\Component\Messenger\Middleware\MiddlewareInterface;
+use Symfony\Component\Messenger\Middleware\StackInterface;
+
+/**
+ * Messenger middleware for correlation ID propagation in async workers.
+ *
+ * - Extracts correlation ID from message stamp if present (propagated from HTTP request)
+ * - Otherwise uses existing ID (synchronous dispatch) or generates new one (async worker)
+ * - Only clears after handling in async context to prevent leakage between messages
+ *
+ * IMPORTANT: We must NOT clear the correlation ID during synchronous dispatch
+ * within an HTTP request, as it would break traceability for the rest of the request.
+ *
+ * @see Story 1.7 - T3: Correlation ID
+ */
+final readonly class CorrelationIdMiddleware implements MiddlewareInterface
+{
+    public function handle(Envelope $envelope, StackInterface $stack): Envelope
+    {
+        // Check if we already have a correlation ID (from HTTP middleware)
+        $existingId = CorrelationIdHolder::get();
+
+        // Extract correlation ID from stamp if present (async message from HTTP)
+        $stamp = $envelope->last(CorrelationIdStamp::class);
+
+        if ($stamp instanceof CorrelationIdStamp) {
+            // Async worker receiving message from HTTP - use stamp's ID
+            $correlationId = CorrelationId::fromString($stamp->correlationId);
+            CorrelationIdHolder::set($correlationId);
+            $shouldClear = true; // Clear after async handling
+        } elseif ($existingId !== null) {
+            // Synchronous dispatch within HTTP request - keep existing ID
+            $shouldClear = false; // Don't clear - HTTP middleware will handle it
+        } else {
+            // Async worker with no stamp - generate new ID for this message
+            $correlationId = CorrelationId::generate();
+            CorrelationIdHolder::set($correlationId);
+            $shouldClear = true; // Clear after handling
+        }
+
+        try {
+            return $stack->next()->handle($envelope, $stack);
+        } finally {
+            // Only clear in async context to prevent leakage between messages
+            // Don't clear during synchronous dispatch - HTTP middleware handles that
+            if ($shouldClear) {
+                CorrelationIdHolder::clear();
+            }
+        }
+    }
+}
diff --git a/backend/src/Shared/Infrastructure/Messenger/CorrelationIdStamp.php b/backend/src/Shared/Infrastructure/Messenger/CorrelationIdStamp.php
new file mode 100644
index 0000000..bd2b1ad
--- /dev/null
+++ b/backend/src/Shared/Infrastructure/Messenger/CorrelationIdStamp.php
@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Shared\Infrastructure\Messenger;
+
+use Symfony\Component\Messenger\Stamp\StampInterface;
+
+/**
+ * Stamp to propagate correlation ID from HTTP request to async message handlers.
+ *
+ * Added automatically by AddCorrelationIdStampMiddleware when dispatching messages.
+ *
+ * @see Story 1.7 - T3: Correlation ID
+ */
+final readonly class CorrelationIdStamp implements StampInterface
+{
+    public function __construct(
+        public string $correlationId,
+    ) {
+    }
+}
diff --git a/backend/src/Shared/Infrastructure/Middleware/CorrelationIdMiddleware.php b/backend/src/Shared/Infrastructure/Middleware/CorrelationIdMiddleware.php
new file mode 100644
index 0000000..747118e
--- /dev/null
+++ b/backend/src/Shared/Infrastructure/Middleware/CorrelationIdMiddleware.php
@@ -0,0 +1,113 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Shared\Infrastructure\Middleware;
+
+use App\Shared\Domain\CorrelationId;
+use App\Shared\Infrastructure\Audit\CorrelationIdHolder;
+use InvalidArgumentException;
+use Symfony\Component\EventDispatcher\Attribute\AsEventListener;
+use Symfony\Component\HttpKernel\Event\ExceptionEvent;
+use Symfony\Component\HttpKernel\Event\RequestEvent;
+use Symfony\Component\HttpKernel\Event\ResponseEvent;
+use Symfony\Component\HttpKernel\Event\TerminateEvent;
+use Symfony\Component\HttpKernel\KernelEvents;
+
+/**
+ * Generates or propagates correlation ID for request tracing.
+ *
+ * - If X-Correlation-Id header exists, uses it (distributed tracing)
+ * - Otherwise generates a new UUID v7
+ * - Stores in CorrelationIdHolder for access anywhere in the request
+ * - Adds X-Correlation-Id header to response
+ * - Clears on request termination (and defensively on exception)
+ *
+ * @see Story 1.7 - T3: Correlation ID
+ */
+final readonly class CorrelationIdMiddleware
+{
+    public const string HEADER_NAME = 'X-Correlation-Id';
+
+    #[AsEventListener(event: KernelEvents::REQUEST, priority: 255)]
+    public function onKernelRequest(RequestEvent $event): void
+    {
+        if (!$event->isMainRequest()) {
+            return;
+        }
+
+        // Defensive cleanup: if previous request didn't terminate properly
+        // (edge case: fatal error, script termination), clear stale ID
+        CorrelationIdHolder::clear();
+
+        $request = $event->getRequest();
+        $existingId = $request->headers->get(self::HEADER_NAME);
+
+        $correlationId = $this->parseOrGenerate($existingId);
+
+        CorrelationIdHolder::set($correlationId);
+
+        // Also store in request attributes for easy access
+        $request->attributes->set('correlation_id', $correlationId);
+    }
+
+    #[AsEventListener(event: KernelEvents::RESPONSE, priority: -255)]
+    public function onKernelResponse(ResponseEvent $event): void
+    {
+        if (!$event->isMainRequest()) {
+            return;
+        }
+
+        $correlationId = CorrelationIdHolder::get();
+        if ($correlationId !== null) {
+            $event->getResponse()->headers->set(
+                self::HEADER_NAME,
+                $correlationId->value(),
+            );
+        }
+    }
+
+    /**
+     * Store correlation ID in exception for error logging before cleanup.
+     *
+     * Priority -255: run after other exception handlers that might need the ID.
+     */
+    #[AsEventListener(event: KernelEvents::EXCEPTION, priority: -255)]
+    public function onKernelException(ExceptionEvent $event): void
+    {
+        $correlationId = CorrelationIdHolder::get();
+        if ($correlationId === null) {
+            return;
+        }
+
+        // Add correlation ID to exception context if possible
+        $exception = $event->getThrowable();
+        if (method_exists($exception, 'setCorrelationId')) {
+            $exception->setCorrelationId($correlationId->value());
+        }
+    }
+
+    #[AsEventListener(event: KernelEvents::TERMINATE)]
+    public function onKernelTerminate(TerminateEvent $event): void
+    {
+        CorrelationIdHolder::clear();
+    }
+
+    /**
+     * Parse existing correlation ID or generate new one if invalid.
+     *
+     * We're lenient with malformed input - just generate a fresh ID.
+     */
+    private function parseOrGenerate(?string $existingId): CorrelationId
+    {
+        if ($existingId === null) {
+            return CorrelationId::generate();
+        }
+
+        try {
+            return CorrelationId::fromString($existingId);
+        } catch (InvalidArgumentException) {
+            return CorrelationId::generate();
+        }
+    }
+}
diff --git a/backend/tests/Functional/Administration/Api/ActivationEndpointsTest.php b/backend/tests/Functional/Administration/Api/ActivationEndpointsTest.php
new file mode 100644
index 0000000..93a0bf2
--- /dev/null
+++ b/backend/tests/Functional/Administration/Api/ActivationEndpointsTest.php
@@ -0,0 +1,102 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Functional\Administration\Api;
+
+use ApiPlatform\Symfony\Bundle\Test\ApiTestCase;
+use PHPUnit\Framework\Attributes\Test;
+
+/**
+ * [P0] Functional tests for account activation endpoints.
+ *
+ * Verifies:
+ * - Token info endpoint accessibility (public)
+ * - Activate endpoint accessibility (public)
+ * - Token validation
+ * - Password requirements validation
+ */
+final class ActivationEndpointsTest extends ApiTestCase
+{
+    protected static ?bool $alwaysBootKernel = true;
+
+    #[Test]
+    public function activationTokenInfoEndpointIsAccessibleWithoutAuthentication(): void
+    {
+        // GIVEN: No authentication
+        $client = static::createClient();
+
+        // WHEN: Requesting token info for an invalid token
+        $response = $client->request('GET', '/api/activation-tokens/550e8400-e29b-41d4-a716-446655440000', [
+            'headers' => [
+                'Host' => 'localhost',
+            ],
+        ]);
+
+        // THEN: Returns 404 (not 401) because endpoint is public
+        // Invalid token returns 404 Not Found
+        self::assertResponseStatusCodeSame(404);
+    }
+
+    #[Test]
+    public function activateEndpointIsAccessibleWithoutAuthentication(): void
+    {
+        // GIVEN: No authentication
+        $client = static::createClient();
+
+        // WHEN: Attempting to activate with invalid token
+        $response = $client->request('POST', '/api/activate', [
+            'json' => [
+                'tokenValue' => '550e8400-e29b-41d4-a716-446655440000',
+                'password' => 'ValidPassword123!',
+            ],
+            'headers' => [
+                'Host' => 'localhost',
+            ],
+        ]);
+
+        // THEN: Returns 404 (token not found) not 401 (unauthorized)
+        // The endpoint is accessible without JWT, it validates the token's existence
+        self::assertNotEquals(401, $response->getStatusCode(), 'Activation endpoint should be accessible without JWT');
+        self::assertResponseStatusCodeSame(404);
+    }
+
+    #[Test]
+    public function activateEndpointValidatesPasswordRequirements(): void
+    {
+        // GIVEN: No authentication
+        $client = static::createClient();
+
+        // WHEN: Attempting activation with weak password
+        $response = $client->request('POST', '/api/activate', [
+            'json' => [
+                'tokenValue' => '550e8400-e29b-41d4-a716-446655440000',
+                'password' => 'weak', // Too short, no uppercase, no number, no special char
+            ],
+            'headers' => [
+                'Host' => 'localhost',
+            ],
+        ]);
+
+        // THEN: Returns 422 Unprocessable Entity for validation errors
+        self::assertResponseStatusCodeSame(422);
+    }
+
+    #[Test]
+    public function activateEndpointRequiresTokenAndPassword(): void
+    {
+        // GIVEN: No authentication
+        $client = static::createClient();
+
+        // WHEN: Attempting activation without required fields
+        $response = $client->request('POST', '/api/activate', [
+            'json' => [],
+            'headers' => [
+                'Host' => 'localhost',
+            ],
+        ]);
+
+        // THEN: Returns 422 for missing required fields
+        self::assertResponseStatusCodeSame(422);
+    }
+}
diff --git a/backend/tests/Functional/Administration/Api/RefreshTokenEndpointTest.php b/backend/tests/Functional/Administration/Api/RefreshTokenEndpointTest.php
new file mode 100644
index 0000000..ef85e5d
--- /dev/null
+++ b/backend/tests/Functional/Administration/Api/RefreshTokenEndpointTest.php
@@ -0,0 +1,105 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Functional\Administration\Api;
+
+use ApiPlatform\Symfony\Bundle\Test\ApiTestCase;
+use PHPUnit\Framework\Attributes\Test;
+
+/**
+ * [P0] Functional tests for the refresh token endpoint.
+ *
+ * Verifies:
+ * - Endpoint accessibility
+ * - Missing token handling (401)
+ * - Invalid token handling
+ * - Cookie-based authentication
+ */
+final class RefreshTokenEndpointTest extends ApiTestCase
+{
+    protected static ?bool $alwaysBootKernel = true;
+
+    #[Test]
+    public function refreshEndpointReturns401WithoutCookie(): void
+    {
+        // GIVEN: No refresh_token cookie
+        $client = static::createClient();
+
+        // WHEN: Calling refresh endpoint
+        $response = $client->request('POST', '/api/token/refresh', [
+            'json' => [],
+            'headers' => [
+                'Host' => 'localhost',
+            ],
+        ]);
+
+        // THEN: Returns 401 Unauthorized
+        self::assertResponseStatusCodeSame(401);
+    }
+
+    #[Test]
+    public function logoutEndpointIsAccessibleWithoutToken(): void
+    {
+        // GIVEN: No authentication
+        $client = static::createClient();
+
+        // WHEN: Calling logout endpoint
+        $response = $client->request('POST', '/api/token/logout', [
+            'json' => [],
+            'headers' => [
+                'Host' => 'localhost',
+            ],
+        ]);
+
+        // THEN: Returns 200 OK (idempotent - no token to invalidate)
+        self::assertResponseIsSuccessful();
+    }
+
+    #[Test]
+    public function logoutEndpointClearsCookies(): void
+    {
+        // GIVEN: A client
+        $client = static::createClient();
+
+        // WHEN: Calling logout
+        $response = $client->request('POST', '/api/token/logout', [
+            'headers' => [
+                'Host' => 'localhost',
+                'Cookie' => 'refresh_token=some-token-value',
+            ],
+        ]);
+
+        // THEN: Response sets expired cookies
+        $setCookieHeaders = $response->getHeaders(false)['set-cookie'] ?? [];
+        $this->assertNotEmpty($setCookieHeaders);
+
+        $hasClearedCookie = false;
+        foreach ($setCookieHeaders as $cookie) {
+            if (str_contains($cookie, 'refresh_token=') && str_contains($cookie, 'expires=')) {
+                $hasClearedCookie = true;
+                break;
+            }
+        }
+        $this->assertTrue($hasClearedCookie, 'Should set expired refresh_token cookie');
+    }
+
+    #[Test]
+    public function refreshEndpointWithInvalidTokenReturns401(): void
+    {
+        // GIVEN: An invalid/malformed token in cookie
+        $client = static::createClient();
+
+        // WHEN: Calling refresh with invalid cookie
+        $response = $client->request('POST', '/api/token/refresh', [
+            'json' => [],
+            'headers' => [
+                'Host' => 'localhost',
+                'Cookie' => 'refresh_token=invalid-token-format',
+            ],
+        ]);
+
+        // THEN: Returns 401 Unauthorized
+        self::assertResponseStatusCodeSame(401);
+    }
+}
diff --git a/backend/tests/Unit/Administration/Infrastructure/Api/Controller/LogoutControllerTest.php b/backend/tests/Unit/Administration/Infrastructure/Api/Controller/LogoutControllerTest.php
new file mode 100644
index 0000000..37b3508
--- /dev/null
+++ b/backend/tests/Unit/Administration/Infrastructure/Api/Controller/LogoutControllerTest.php
@@ -0,0 +1,305 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Administration\Infrastructure\Api\Controller;
+
+use App\Administration\Domain\Event\Deconnexion;
+use App\Administration\Domain\Model\RefreshToken\DeviceFingerprint;
+use App\Administration\Domain\Model\RefreshToken\RefreshToken;
+use App\Administration\Domain\Model\User\UserId;
+use App\Administration\Domain\Repository\RefreshTokenRepository;
+use App\Administration\Domain\Repository\SessionRepository;
+use App\Administration\Infrastructure\Api\Controller\LogoutController;
+use App\Shared\Domain\Clock;
+use App\Shared\Domain\DomainEvent;
+use App\Shared\Domain\Tenant\TenantId;
+use DateTimeImmutable;
+use Override;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Messenger\Envelope;
+use Symfony\Component\Messenger\MessageBusInterface;
+
+/**
+ * [P0] Tests for LogoutController - critical session invalidation.
+ *
+ * Verifies:
+ * - Token family invalidation on logout
+ * - Session deletion
+ * - Cookie clearing
+ * - Deconnexion event dispatch
+ * - Graceful handling of missing/malformed tokens
+ */
+final class LogoutControllerTest extends TestCase
+{
+    private const string USER_ID = '550e8400-e29b-41d4-a716-446655440001';
+    private const string TENANT_ID = '550e8400-e29b-41d4-a716-446655440002';
+    private const string IP_ADDRESS = '192.168.1.100';
+    private const string USER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64)';
+
+    private RefreshTokenRepository $refreshTokenRepository;
+    private SessionRepository $sessionRepository;
+    private Clock $clock;
+    /** @var DomainEvent[] */
+    private array $dispatchedEvents = [];
+    private LogoutController $controller;
+
+    protected function setUp(): void
+    {
+        $this->refreshTokenRepository = $this->createMock(RefreshTokenRepository::class);
+        $this->sessionRepository = $this->createMock(SessionRepository::class);
+
+        $this->clock = new class implements Clock {
+            #[Override]
+            public function now(): DateTimeImmutable
+            {
+                return new DateTimeImmutable('2026-01-28 10:00:00');
+            }
+        };
+
+        $this->dispatchedEvents = [];
+        $eventBus = new class($this->dispatchedEvents) implements MessageBusInterface {
+            /** @param DomainEvent[] $events */
+            public function __construct(private array &$events)
+            {
+            }
+
+            #[Override]
+            public function dispatch(object $message, array $stamps = []): Envelope
+            {
+                $this->events[] = $message;
+
+                return new Envelope($message);
+            }
+        };
+
+        $this->controller = new LogoutController(
+            $this->refreshTokenRepository,
+            $this->sessionRepository,
+            $eventBus,
+            $this->clock,
+        );
+    }
+
+    #[Test]
+    public function itInvalidatesTokenFamilyOnLogout(): void
+    {
+        // GIVEN: A request with a valid refresh token cookie
+        $refreshToken = $this->createRefreshToken();
+        $tokenString = $refreshToken->toTokenString();
+
+        $request = Request::create('/api/token/logout', 'POST', [], [
+            'refresh_token' => $tokenString,
+        ], [], [
+            'REMOTE_ADDR' => self::IP_ADDRESS,
+            'HTTP_USER_AGENT' => self::USER_AGENT,
+        ]);
+
+        $this->refreshTokenRepository
+            ->expects($this->once())
+            ->method('find')
+            ->with($refreshToken->id)
+            ->willReturn($refreshToken);
+
+        // THEN: Family should be invalidated
+        $this->refreshTokenRepository
+            ->expects($this->once())
+            ->method('invalidateFamily')
+            ->with($refreshToken->familyId);
+
+        // WHEN: Logout is invoked
+        $response = ($this->controller)($request);
+
+        // THEN: Returns success
+        $this->assertSame(Response::HTTP_OK, $response->getStatusCode());
+    }
+
+    #[Test]
+    public function itDeletesSessionOnLogout(): void
+    {
+        // GIVEN: A valid refresh token
+        $refreshToken = $this->createRefreshToken();
+
+        $request = Request::create('/api/token/logout', 'POST', [], [
+            'refresh_token' => $refreshToken->toTokenString(),
+        ], [], [
+            'REMOTE_ADDR' => self::IP_ADDRESS,
+            'HTTP_USER_AGENT' => self::USER_AGENT,
+        ]);
+
+        $this->refreshTokenRepository
+            ->method('find')
+            ->willReturn($refreshToken);
+
+        // THEN: Session should be deleted
+        $this->sessionRepository
+            ->expects($this->once())
+            ->method('delete')
+            ->with($refreshToken->familyId);
+
+        // WHEN: Logout is invoked
+        ($this->controller)($request);
+    }
+
+    #[Test]
+    public function itDispatchesDeconnexionEvent(): void
+    {
+        // GIVEN: A valid refresh token
+        $refreshToken = $this->createRefreshToken();
+
+        $request = Request::create('/api/token/logout', 'POST', [], [
+            'refresh_token' => $refreshToken->toTokenString(),
+        ], [], [
+            'REMOTE_ADDR' => self::IP_ADDRESS,
+            'HTTP_USER_AGENT' => self::USER_AGENT,
+        ]);
+
+        $this->refreshTokenRepository
+            ->method('find')
+            ->willReturn($refreshToken);
+
+        // WHEN: Logout is invoked
+        ($this->controller)($request);
+
+        // THEN: Deconnexion event is dispatched with correct data
+        $logoutEvents = array_filter(
+            $this->dispatchedEvents,
+            static fn ($e) => $e instanceof Deconnexion,
+        );
+        $this->assertCount(1, $logoutEvents);
+
+        $event = reset($logoutEvents);
+        $this->assertSame((string) $refreshToken->userId, $event->userId);
+        $this->assertSame((string) $refreshToken->familyId, $event->familyId);
+        $this->assertSame(self::IP_ADDRESS, $event->ipAddress);
+        $this->assertSame(self::USER_AGENT, $event->userAgent);
+    }
+
+    #[Test]
+    public function itClearsCookiesOnLogout(): void
+    {
+        // GIVEN: A valid refresh token
+        $refreshToken = $this->createRefreshToken();
+
+        $request = Request::create('/api/token/logout', 'POST', [], [
+            'refresh_token' => $refreshToken->toTokenString(),
+        ], [], [
+            'REMOTE_ADDR' => self::IP_ADDRESS,
+            'HTTP_USER_AGENT' => self::USER_AGENT,
+        ]);
+
+        $this->refreshTokenRepository
+            ->method('find')
+            ->willReturn($refreshToken);
+
+        // WHEN: Logout is invoked
+        $response = ($this->controller)($request);
+
+        // THEN: Cookies are cleared (expired)
+        $cookies = $response->headers->getCookies();
+        $this->assertCount(2, $cookies); // /api and /api/token (legacy)
+
+        foreach ($cookies as $cookie) {
+            $this->assertSame('refresh_token', $cookie->getName());
+            $this->assertSame('', $cookie->getValue());
+            $this->assertTrue($cookie->isCleared()); // Expiry in the past
+        }
+    }
+
+    #[Test]
+    public function itHandlesMissingCookieGracefully(): void
+    {
+        // GIVEN: A request without refresh_token cookie
+        $request = Request::create('/api/token/logout', 'POST', [], [], [], [
+            'REMOTE_ADDR' => self::IP_ADDRESS,
+            'HTTP_USER_AGENT' => self::USER_AGENT,
+        ]);
+
+        // THEN: No repository operations
+        $this->refreshTokenRepository
+            ->expects($this->never())
+            ->method('find');
+
+        $this->refreshTokenRepository
+            ->expects($this->never())
+            ->method('invalidateFamily');
+
+        $this->sessionRepository
+            ->expects($this->never())
+            ->method('delete');
+
+        // WHEN: Logout is invoked
+        $response = ($this->controller)($request);
+
+        // THEN: Still returns success (idempotent)
+        $this->assertSame(Response::HTTP_OK, $response->getStatusCode());
+
+        // THEN: Cookies are still cleared
+        $this->assertNotEmpty($response->headers->getCookies());
+    }
+
+    #[Test]
+    public function itHandlesMalformedTokenGracefully(): void
+    {
+        // GIVEN: A request with malformed token
+        $request = Request::create('/api/token/logout', 'POST', [], [
+            'refresh_token' => 'malformed-token-not-base64',
+        ], [], [
+            'REMOTE_ADDR' => self::IP_ADDRESS,
+            'HTTP_USER_AGENT' => self::USER_AGENT,
+        ]);
+
+        // THEN: No repository operations (exception caught)
+        $this->refreshTokenRepository
+            ->expects($this->never())
+            ->method('invalidateFamily');
+
+        // WHEN: Logout is invoked
+        $response = ($this->controller)($request);
+
+        // THEN: Still returns success
+        $this->assertSame(Response::HTTP_OK, $response->getStatusCode());
+    }
+
+    #[Test]
+    public function itHandlesNonExistentTokenGracefully(): void
+    {
+        // GIVEN: A valid token format but not in database
+        $refreshToken = $this->createRefreshToken();
+
+        $request = Request::create('/api/token/logout', 'POST', [], [
+            'refresh_token' => $refreshToken->toTokenString(),
+        ], [], [
+            'REMOTE_ADDR' => self::IP_ADDRESS,
+            'HTTP_USER_AGENT' => self::USER_AGENT,
+        ]);
+
+        $this->refreshTokenRepository
+            ->method('find')
+            ->willReturn(null);
+
+        // THEN: No invalidation attempted
+        $this->refreshTokenRepository
+            ->expects($this->never())
+            ->method('invalidateFamily');
+
+        // WHEN: Logout is invoked
+        $response = ($this->controller)($request);
+
+        // THEN: Still returns success (idempotent)
+        $this->assertSame(Response::HTTP_OK, $response->getStatusCode());
+    }
+
+    private function createRefreshToken(): RefreshToken
+    {
+        return RefreshToken::create(
+            userId: UserId::fromString(self::USER_ID),
+            tenantId: TenantId::fromString(self::TENANT_ID),
+            deviceFingerprint: DeviceFingerprint::fromRequest(self::USER_AGENT, self::IP_ADDRESS),
+            issuedAt: $this->clock->now(),
+        );
+    }
+}
diff --git a/backend/tests/Unit/Administration/Infrastructure/Persistence/InMemory/InMemoryRefreshTokenRepositoryTest.php b/backend/tests/Unit/Administration/Infrastructure/Persistence/InMemory/InMemoryRefreshTokenRepositoryTest.php
new file mode 100644
index 0000000..3891760
--- /dev/null
+++ b/backend/tests/Unit/Administration/Infrastructure/Persistence/InMemory/InMemoryRefreshTokenRepositoryTest.php
@@ -0,0 +1,249 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Administration\Infrastructure\Persistence\InMemory;
+
+use App\Administration\Domain\Model\RefreshToken\DeviceFingerprint;
+use App\Administration\Domain\Model\RefreshToken\RefreshToken;
+use App\Administration\Domain\Model\RefreshToken\TokenFamilyId;
+use App\Administration\Domain\Model\User\UserId;
+use App\Administration\Infrastructure\Persistence\InMemory\InMemoryRefreshTokenRepository;
+use App\Shared\Domain\Tenant\TenantId;
+use DateTimeImmutable;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * [P1] Tests for InMemoryRefreshTokenRepository.
+ *
+ * Verifies:
+ * - Token save and retrieval
+ * - Token deletion
+ * - Family invalidation (all tokens in family)
+ * - User invalidation (all families for user)
+ * - Index maintenance
+ */
+final class InMemoryRefreshTokenRepositoryTest extends TestCase
+{
+    private const string USER_ID = '550e8400-e29b-41d4-a716-446655440001';
+    private const string USER_ID_2 = '550e8400-e29b-41d4-a716-446655440003';
+    private const string TENANT_ID = '550e8400-e29b-41d4-a716-446655440002';
+
+    private InMemoryRefreshTokenRepository $repository;
+    private DateTimeImmutable $now;
+
+    protected function setUp(): void
+    {
+        $this->repository = new InMemoryRefreshTokenRepository();
+        $this->now = new DateTimeImmutable('2026-01-28 10:00:00');
+    }
+
+    #[Test]
+    public function itSavesAndRetrievesToken(): void
+    {
+        // GIVEN: A refresh token
+        $token = $this->createToken(self::USER_ID);
+
+        // WHEN: Token is saved
+        $this->repository->save($token);
+
+        // THEN: Token can be retrieved by ID
+        $found = $this->repository->find($token->id);
+        $this->assertNotNull($found);
+        $this->assertSame((string) $token->id, (string) $found->id);
+        $this->assertSame((string) $token->familyId, (string) $found->familyId);
+        $this->assertSame((string) $token->userId, (string) $found->userId);
+    }
+
+    #[Test]
+    public function itReturnsNullForNonExistentToken(): void
+    {
+        // GIVEN: Empty repository
+
+        // WHEN: Searching for non-existent token
+        $token = $this->createToken(self::USER_ID);
+        $found = $this->repository->find($token->id);
+
+        // THEN: Returns null
+        $this->assertNull($found);
+    }
+
+    #[Test]
+    public function itDeletesTokenById(): void
+    {
+        // GIVEN: A saved token
+        $token = $this->createToken(self::USER_ID);
+        $this->repository->save($token);
+
+        // WHEN: Token is deleted
+        $this->repository->delete($token->id);
+
+        // THEN: Token is no longer found
+        $found = $this->repository->find($token->id);
+        $this->assertNull($found);
+    }
+
+    #[Test]
+    public function itInvalidatesEntireFamily(): void
+    {
+        // GIVEN: Multiple tokens in the same family
+        $token1 = $this->createToken(self::USER_ID);
+        $token2 = $this->rotateToken($token1);
+        $token3 = $this->rotateToken($token2);
+
+        $this->repository->save($token1);
+        $this->repository->save($token2);
+        $this->repository->save($token3);
+
+        // WHEN: Family is invalidated
+        $this->repository->invalidateFamily($token1->familyId);
+
+        // THEN: All tokens in family are deleted
+        $this->assertNull($this->repository->find($token1->id));
+        $this->assertNull($this->repository->find($token2->id));
+        $this->assertNull($this->repository->find($token3->id));
+    }
+
+    #[Test]
+    public function itDoesNotAffectOtherFamilies(): void
+    {
+        // GIVEN: Tokens in different families
+        $token1 = $this->createToken(self::USER_ID);
+        $token2 = $this->createToken(self::USER_ID); // Different family (new login session)
+
+        $this->repository->save($token1);
+        $this->repository->save($token2);
+
+        // WHEN: One family is invalidated
+        $this->repository->invalidateFamily($token1->familyId);
+
+        // THEN: Other family is intact
+        $this->assertNull($this->repository->find($token1->id));
+        $this->assertNotNull($this->repository->find($token2->id));
+    }
+
+    #[Test]
+    public function itInvalidatesAllFamiliesForUser(): void
+    {
+        // GIVEN: Multiple families for the same user (multiple devices)
+        $token1 = $this->createToken(self::USER_ID);
+        $token2 = $this->createToken(self::USER_ID);
+        $token3 = $this->createToken(self::USER_ID);
+
+        $this->repository->save($token1);
+        $this->repository->save($token2);
+        $this->repository->save($token3);
+
+        // All belong to same user but different families
+        $userId = UserId::fromString(self::USER_ID);
+
+        // Verify user has active sessions
+        $this->assertTrue($this->repository->hasActiveSessionsForUser($userId));
+
+        // WHEN: All tokens for user are invalidated
+        $this->repository->invalidateAllForUser($userId);
+
+        // THEN: No sessions remain for user
+        $this->assertFalse($this->repository->hasActiveSessionsForUser($userId));
+        $this->assertNull($this->repository->find($token1->id));
+        $this->assertNull($this->repository->find($token2->id));
+        $this->assertNull($this->repository->find($token3->id));
+    }
+
+    #[Test]
+    public function itDoesNotAffectOtherUsers(): void
+    {
+        // GIVEN: Tokens for different users
+        $token1 = $this->createToken(self::USER_ID);
+        $token2 = $this->createToken(self::USER_ID_2);
+
+        $this->repository->save($token1);
+        $this->repository->save($token2);
+
+        // WHEN: First user's tokens are invalidated
+        $this->repository->invalidateAllForUser(UserId::fromString(self::USER_ID));
+
+        // THEN: Second user's token is intact
+        $this->assertNull($this->repository->find($token1->id));
+        $this->assertNotNull($this->repository->find($token2->id));
+    }
+
+    #[Test]
+    public function itTracksActiveSessionsForUser(): void
+    {
+        // GIVEN: No tokens for user
+        $userId = UserId::fromString(self::USER_ID);
+        $this->assertFalse($this->repository->hasActiveSessionsForUser($userId));
+
+        // WHEN: Token is saved
+        $token = $this->createToken(self::USER_ID);
+        $this->repository->save($token);
+
+        // THEN: User has active sessions
+        $this->assertTrue($this->repository->hasActiveSessionsForUser($userId));
+    }
+
+    #[Test]
+    public function itHandlesInvalidationOfNonExistentFamily(): void
+    {
+        // GIVEN: Non-existent family ID
+        $familyId = TokenFamilyId::generate();
+
+        // WHEN: Invalidating non-existent family
+        $this->repository->invalidateFamily($familyId);
+
+        // THEN: No exception thrown (idempotent operation)
+        $this->assertTrue(true);
+    }
+
+    #[Test]
+    public function itHandlesInvalidationOfNonExistentUser(): void
+    {
+        // GIVEN: Non-existent user ID
+        $userId = UserId::fromString(self::USER_ID);
+
+        // WHEN: Invalidating non-existent user's tokens
+        $this->repository->invalidateAllForUser($userId);
+
+        // THEN: No exception thrown (idempotent operation)
+        $this->assertTrue(true);
+    }
+
+    #[Test]
+    public function itHandlesDuplicateSavesIdempotently(): void
+    {
+        // GIVEN: A token
+        $token = $this->createToken(self::USER_ID);
+
+        // WHEN: Token is saved multiple times
+        $this->repository->save($token);
+        $this->repository->save($token);
+        $this->repository->save($token);
+
+        // THEN: Token exists once (no duplicates in indexes)
+        $found = $this->repository->find($token->id);
+        $this->assertNotNull($found);
+
+        // Invalidating family should clean everything properly
+        $this->repository->invalidateFamily($token->familyId);
+        $this->assertNull($this->repository->find($token->id));
+    }
+
+    private function createToken(string $userId): RefreshToken
+    {
+        return RefreshToken::create(
+            userId: UserId::fromString($userId),
+            tenantId: TenantId::fromString(self::TENANT_ID),
+            deviceFingerprint: DeviceFingerprint::fromRequest('Mozilla/5.0', '192.168.1.1'),
+            issuedAt: $this->now,
+        );
+    }
+
+    private function rotateToken(RefreshToken $token): RefreshToken
+    {
+        [$newToken, $oldToken] = $token->rotate($this->now->modify('+1 minute'));
+
+        return $newToken;
+    }
+}
diff --git a/backend/tests/Unit/Administration/Infrastructure/Security/LoginSuccessHandlerTest.php b/backend/tests/Unit/Administration/Infrastructure/Security/LoginSuccessHandlerTest.php
new file mode 100644
index 0000000..29dead9
--- /dev/null
+++ b/backend/tests/Unit/Administration/Infrastructure/Security/LoginSuccessHandlerTest.php
@@ -0,0 +1,331 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Administration\Infrastructure\Security;
+
+use App\Administration\Application\Port\GeoLocationService;
+use App\Administration\Application\Service\RefreshTokenManager;
+use App\Administration\Domain\Event\ConnexionReussie;
+use App\Administration\Domain\Model\Session\Location;
+use App\Administration\Domain\Model\Session\Session;
+use App\Administration\Domain\Model\User\UserId;
+use App\Administration\Domain\Repository\SessionRepository;
+use App\Administration\Infrastructure\Persistence\InMemory\InMemoryRefreshTokenRepository;
+use App\Administration\Infrastructure\Security\LoginSuccessHandler;
+use App\Administration\Infrastructure\Security\SecurityUser;
+use App\Shared\Domain\Clock;
+use App\Shared\Domain\DomainEvent;
+use App\Shared\Domain\Tenant\TenantId;
+use App\Shared\Infrastructure\RateLimit\LoginRateLimiterInterface;
+use DateTimeImmutable;
+use Lexik\Bundle\JWTAuthenticationBundle\Event\AuthenticationSuccessEvent;
+use Override;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\RequestStack;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Messenger\Envelope;
+use Symfony\Component\Messenger\MessageBusInterface;
+use Symfony\Component\Security\Core\User\UserInterface;
+
+/**
+ * [P0] Tests for LoginSuccessHandler - critical authentication flow.
+ *
+ * Verifies:
+ * - Refresh token creation on successful login
+ * - Session creation with device info and geolocation
+ * - Rate limiter reset after successful login
+ * - ConnexionReussie event dispatch
+ * - HttpOnly cookie configuration
+ */
+final class LoginSuccessHandlerTest extends TestCase
+{
+    private const string USER_ID = '550e8400-e29b-41d4-a716-446655440001';
+    private const string TENANT_ID = '550e8400-e29b-41d4-a716-446655440002';
+    private const string EMAIL = 'user@example.com';
+    private const string IP_ADDRESS = '192.168.1.100';
+    private const string USER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64)';
+
+    private InMemoryRefreshTokenRepository $refreshTokenRepository;
+    private RefreshTokenManager $refreshTokenManager;
+    private SessionRepository $sessionRepository;
+    private GeoLocationService $geoLocationService;
+    private LoginRateLimiterInterface $rateLimiter;
+    private Clock $clock;
+    private RequestStack $requestStack;
+    /** @var DomainEvent[] */
+    private array $dispatchedEvents = [];
+    private LoginSuccessHandler $handler;
+
+    protected function setUp(): void
+    {
+        $this->clock = new class implements Clock {
+            #[Override]
+            public function now(): DateTimeImmutable
+            {
+                return new DateTimeImmutable('2026-01-28 10:00:00');
+            }
+        };
+
+        $this->refreshTokenRepository = new InMemoryRefreshTokenRepository();
+        $this->refreshTokenManager = new RefreshTokenManager(
+            $this->refreshTokenRepository,
+            $this->clock,
+        );
+
+        $this->sessionRepository = $this->createMock(SessionRepository::class);
+        $this->geoLocationService = $this->createMock(GeoLocationService::class);
+        $this->rateLimiter = $this->createMock(LoginRateLimiterInterface::class);
+        $this->requestStack = new RequestStack();
+
+        $this->dispatchedEvents = [];
+        $eventBus = new class($this->dispatchedEvents) implements MessageBusInterface {
+            /** @param DomainEvent[] $events */
+            public function __construct(private array &$events)
+            {
+            }
+
+            #[Override]
+            public function dispatch(object $message, array $stamps = []): Envelope
+            {
+                $this->events[] = $message;
+
+                return new Envelope($message);
+            }
+        };
+
+        $this->handler = new LoginSuccessHandler(
+            $this->refreshTokenManager,
+            $this->sessionRepository,
+            $this->geoLocationService,
+            $this->rateLimiter,
+            $eventBus,
+            $this->clock,
+            $this->requestStack,
+        );
+    }
+
+    #[Test]
+    public function itCreatesRefreshTokenOnSuccessfulLogin(): void
+    {
+        // GIVEN: A successful authentication event with SecurityUser
+        $request = $this->createRequest();
+        $this->requestStack->push($request);
+
+        $securityUser = $this->createSecurityUser();
+        $response = new Response();
+        $event = new AuthenticationSuccessEvent(['token' => 'jwt'], $securityUser, $response);
+
+        $this->geoLocationService
+            ->method('locate')
+            ->willReturn(Location::unknown());
+
+        $this->sessionRepository
+            ->expects($this->once())
+            ->method('save')
+            ->with(
+                $this->isInstanceOf(Session::class),
+                $this->greaterThan(0),
+            );
+
+        // WHEN: Handler processes the event
+        $this->handler->onAuthenticationSuccess($event);
+
+        // THEN: Refresh token cookie is set
+        $cookies = $response->headers->getCookies();
+        $this->assertCount(1, $cookies);
+        $this->assertSame('refresh_token', $cookies[0]->getName());
+        $this->assertTrue($cookies[0]->isHttpOnly());
+        $this->assertSame('/api', $cookies[0]->getPath());
+
+        // THEN: Refresh token is saved in repository
+        $this->assertTrue(
+            $this->refreshTokenRepository->hasActiveSessionsForUser(
+                UserId::fromString(self::USER_ID),
+            ),
+        );
+    }
+
+    #[Test]
+    public function itCreatesSessionWithDeviceInfoAndLocation(): void
+    {
+        // GIVEN: A successful authentication with request context
+        $request = $this->createRequest();
+        $this->requestStack->push($request);
+
+        $securityUser = $this->createSecurityUser();
+        $response = new Response();
+        $event = new AuthenticationSuccessEvent(['token' => 'jwt'], $securityUser, $response);
+
+        $expectedLocation = Location::fromIp(self::IP_ADDRESS, 'France', 'Paris');
+
+        $this->geoLocationService
+            ->expects($this->once())
+            ->method('locate')
+            ->with(self::IP_ADDRESS)
+            ->willReturn($expectedLocation);
+
+        $savedSession = null;
+        $this->sessionRepository
+            ->expects($this->once())
+            ->method('save')
+            ->willReturnCallback(static function (Session $session, int $ttl) use (&$savedSession): void {
+                $savedSession = $session;
+            });
+
+        // WHEN: Handler processes the event
+        $this->handler->onAuthenticationSuccess($event);
+
+        // THEN: Session is created with correct data
+        $this->assertNotNull($savedSession);
+        $this->assertSame(self::USER_ID, (string) $savedSession->userId);
+    }
+
+    #[Test]
+    public function itResetsRateLimiterAfterSuccessfulLogin(): void
+    {
+        // GIVEN: A successful authentication
+        $request = $this->createRequest();
+        $this->requestStack->push($request);
+
+        $securityUser = $this->createSecurityUser();
+        $response = new Response();
+        $event = new AuthenticationSuccessEvent(['token' => 'jwt'], $securityUser, $response);
+
+        $this->geoLocationService
+            ->method('locate')
+            ->willReturn(Location::unknown());
+
+        // THEN: Rate limiter should be reset for the user's email
+        $this->rateLimiter
+            ->expects($this->once())
+            ->method('reset')
+            ->with(self::EMAIL);
+
+        // WHEN: Handler processes the event
+        $this->handler->onAuthenticationSuccess($event);
+    }
+
+    #[Test]
+    public function itDispatchesConnexionReussieEvent(): void
+    {
+        // GIVEN: A successful authentication
+        $request = $this->createRequest();
+        $this->requestStack->push($request);
+
+        $securityUser = $this->createSecurityUser();
+        $response = new Response();
+        $event = new AuthenticationSuccessEvent(['token' => 'jwt'], $securityUser, $response);
+
+        $this->geoLocationService
+            ->method('locate')
+            ->willReturn(Location::unknown());
+
+        // WHEN: Handler processes the event
+        $this->handler->onAuthenticationSuccess($event);
+
+        // THEN: ConnexionReussie event is dispatched
+        $loginEvents = array_filter(
+            $this->dispatchedEvents,
+            static fn ($e) => $e instanceof ConnexionReussie,
+        );
+        $this->assertCount(1, $loginEvents);
+
+        $loginEvent = reset($loginEvents);
+        $this->assertSame(self::USER_ID, $loginEvent->userId);
+        $this->assertSame(self::EMAIL, $loginEvent->email);
+        $this->assertSame(self::IP_ADDRESS, $loginEvent->ipAddress);
+    }
+
+    #[Test]
+    public function itIgnoresNonSecurityUserAuthentication(): void
+    {
+        // GIVEN: An authentication event with a non-SecurityUser user
+        $request = $this->createRequest();
+        $this->requestStack->push($request);
+
+        $genericUser = $this->createMock(UserInterface::class);
+        $response = new Response();
+        $event = new AuthenticationSuccessEvent(['token' => 'jwt'], $genericUser, $response);
+
+        // THEN: No operations should be performed
+        $this->sessionRepository
+            ->expects($this->never())
+            ->method('save');
+
+        // WHEN: Handler processes the event
+        $this->handler->onAuthenticationSuccess($event);
+
+        // THEN: No cookies added, no events dispatched
+        $this->assertEmpty($response->headers->getCookies());
+        $this->assertEmpty($this->dispatchedEvents);
+    }
+
+    #[Test]
+    public function itIgnoresEventWithoutRequest(): void
+    {
+        // GIVEN: No request in the stack
+        $securityUser = $this->createSecurityUser();
+        $response = new Response();
+        $event = new AuthenticationSuccessEvent(['token' => 'jwt'], $securityUser, $response);
+
+        // THEN: No operations should be performed
+        $this->sessionRepository
+            ->expects($this->never())
+            ->method('save');
+
+        // WHEN: Handler processes the event
+        $this->handler->onAuthenticationSuccess($event);
+
+        // THEN: No cookies added
+        $this->assertEmpty($response->headers->getCookies());
+    }
+
+    #[Test]
+    public function itSetsSecureCookieOnlyForHttps(): void
+    {
+        // GIVEN: An HTTP request (not HTTPS)
+        $request = Request::create('http://localhost/login', 'POST', [], [], [], [
+            'REMOTE_ADDR' => self::IP_ADDRESS,
+            'HTTP_USER_AGENT' => self::USER_AGENT,
+        ]);
+        $this->requestStack->push($request);
+
+        $securityUser = $this->createSecurityUser();
+        $response = new Response();
+        $event = new AuthenticationSuccessEvent(['token' => 'jwt'], $securityUser, $response);
+
+        $this->geoLocationService
+            ->method('locate')
+            ->willReturn(Location::unknown());
+
+        // WHEN: Handler processes the event
+        $this->handler->onAuthenticationSuccess($event);
+
+        // THEN: Cookie is NOT marked as secure (HTTP)
+        $cookies = $response->headers->getCookies();
+        $this->assertCount(1, $cookies);
+        $this->assertFalse($cookies[0]->isSecure());
+    }
+
+    private function createRequest(): Request
+    {
+        return Request::create('/login', 'POST', [], [], [], [
+            'REMOTE_ADDR' => self::IP_ADDRESS,
+            'HTTP_USER_AGENT' => self::USER_AGENT,
+        ]);
+    }
+
+    private function createSecurityUser(): SecurityUser
+    {
+        return new SecurityUser(
+            userId: UserId::fromString(self::USER_ID),
+            email: self::EMAIL,
+            hashedPassword: '$argon2id$hashed',
+            tenantId: TenantId::fromString(self::TENANT_ID),
+            roles: ['ROLE_PROF'],
+        );
+    }
+}
diff --git a/backend/tests/Unit/Shared/Domain/CorrelationIdTest.php b/backend/tests/Unit/Shared/Domain/CorrelationIdTest.php
index eadc1c3..12ec7ed 100644
--- a/backend/tests/Unit/Shared/Domain/CorrelationIdTest.php
+++ b/backend/tests/Unit/Shared/Domain/CorrelationIdTest.php
@@ -5,6 +5,7 @@ declare(strict_types=1);
 namespace App\Tests\Unit\Shared\Domain;
 
 use App\Shared\Domain\CorrelationId;
+use InvalidArgumentException;
 use PHPUnit\Framework\TestCase;
 use Ramsey\Uuid\Uuid;
 
@@ -48,4 +49,19 @@ final class CorrelationIdTest extends TestCase
 
         $this->assertNotSame($id1->value(), $id2->value());
     }
+
+    public function testFromStringRejectsInvalidUuid(): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionMessage('Invalid correlation ID format');
+
+        CorrelationId::fromString('not-a-valid-uuid');
+    }
+
+    public function testFromStringRejectsEmptyString(): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+
+        CorrelationId::fromString('');
+    }
 }
diff --git a/backend/tests/Unit/Shared/Infrastructure/Audit/AuditLogEntryTest.php b/backend/tests/Unit/Shared/Infrastructure/Audit/AuditLogEntryTest.php
new file mode 100644
index 0000000..72a3a41
--- /dev/null
+++ b/backend/tests/Unit/Shared/Infrastructure/Audit/AuditLogEntryTest.php
@@ -0,0 +1,81 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Shared\Infrastructure\Audit;
+
+use App\Shared\Infrastructure\Audit\AuditLogEntry;
+use PHPUnit\Framework\TestCase;
+use Ramsey\Uuid\Uuid;
+
+/**
+ * @see Story 1.7 - T9: Requetes d'investigation
+ */
+final class AuditLogEntryTest extends TestCase
+{
+    public function testFromDatabaseRow(): void
+    {
+        $id = Uuid::uuid4()->toString();
+        $aggregateId = Uuid::uuid4()->toString();
+        $row = [
+            'id' => $id,
+            'aggregate_type' => 'User',
+            'aggregate_id' => $aggregateId,
+            'event_type' => 'ConnexionReussie',
+            'payload' => '{"email_hash":"abc123","result":"success"}',
+            'metadata' => '{"tenant_id":"tenant-1","user_id":"user-1","correlation_id":"corr-1"}',
+            'occurred_at' => '2026-02-03T10:30:00+00:00',
+            'sequence_number' => '42',
+        ];
+
+        $entry = AuditLogEntry::fromDatabaseRow($row);
+
+        $this->assertEquals($id, $entry->id->toString());
+        $this->assertSame('User', $entry->aggregateType);
+        $this->assertEquals($aggregateId, $entry->aggregateId?->toString());
+        $this->assertSame('ConnexionReussie', $entry->eventType);
+        $this->assertSame(['email_hash' => 'abc123', 'result' => 'success'], $entry->payload);
+        $this->assertSame('tenant-1', $entry->tenantId());
+        $this->assertSame('user-1', $entry->userId());
+        $this->assertSame('corr-1', $entry->correlationId());
+        $this->assertSame(42, $entry->sequenceNumber);
+    }
+
+    public function testFromDatabaseRowWithNullAggregateId(): void
+    {
+        $row = [
+            'id' => Uuid::uuid4()->toString(),
+            'aggregate_type' => 'Export',
+            'aggregate_id' => null,
+            'event_type' => 'ExportGenerated',
+            'payload' => '{}',
+            'metadata' => '{}',
+            'occurred_at' => '2026-02-03T10:30:00+00:00',
+            'sequence_number' => '1',
+        ];
+
+        $entry = AuditLogEntry::fromDatabaseRow($row);
+
+        $this->assertNull($entry->aggregateId);
+    }
+
+    public function testMetadataAccessorsReturnNullWhenMissing(): void
+    {
+        $row = [
+            'id' => Uuid::uuid4()->toString(),
+            'aggregate_type' => 'User',
+            'aggregate_id' => null,
+            'event_type' => 'Test',
+            'payload' => '{}',
+            'metadata' => '{}',
+            'occurred_at' => '2026-02-03T10:30:00+00:00',
+            'sequence_number' => '1',
+        ];
+
+        $entry = AuditLogEntry::fromDatabaseRow($row);
+
+        $this->assertNull($entry->tenantId());
+        $this->assertNull($entry->userId());
+        $this->assertNull($entry->correlationId());
+    }
+}
diff --git a/backend/tests/Unit/Shared/Infrastructure/Audit/AuditLogRepositoryTest.php b/backend/tests/Unit/Shared/Infrastructure/Audit/AuditLogRepositoryTest.php
new file mode 100644
index 0000000..c8946a0
--- /dev/null
+++ b/backend/tests/Unit/Shared/Infrastructure/Audit/AuditLogRepositoryTest.php
@@ -0,0 +1,219 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Shared\Infrastructure\Audit;
+
+use App\Shared\Domain\Tenant\TenantId;
+use App\Shared\Infrastructure\Audit\AuditLogEntry;
+use App\Shared\Infrastructure\Audit\AuditLogRepository;
+use DateTimeImmutable;
+use Doctrine\DBAL\Connection;
+use Doctrine\DBAL\Query\QueryBuilder;
+use Doctrine\DBAL\Result;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
+use Ramsey\Uuid\Uuid;
+
+/**
+ * @see Story 1.7 - T9: Requetes d'investigation
+ */
+final class AuditLogRepositoryTest extends TestCase
+{
+    private Connection&MockObject $connection;
+    private AuditLogRepository $repository;
+
+    protected function setUp(): void
+    {
+        $this->connection = $this->createMock(Connection::class);
+        $this->repository = new AuditLogRepository($this->connection);
+    }
+
+    public function testFindByUserReturnsAuditLogEntries(): void
+    {
+        $userId = Uuid::uuid4();
+        $tenantId = TenantId::generate();
+
+        $rows = [
+            $this->createRowData(),
+            $this->createRowData(),
+        ];
+
+        $queryBuilder = $this->createQueryBuilderMock($rows);
+        $this->connection->method('createQueryBuilder')->willReturn($queryBuilder);
+
+        $result = $this->repository->findByUser($userId, $tenantId);
+
+        $this->assertCount(2, $result);
+        $this->assertContainsOnlyInstancesOf(AuditLogEntry::class, $result);
+    }
+
+    public function testFindByUserAppliesFilters(): void
+    {
+        $userId = Uuid::uuid4();
+        $tenantId = TenantId::generate();
+        $from = new DateTimeImmutable('2026-01-01');
+        $to = new DateTimeImmutable('2026-02-01');
+
+        $queryBuilder = $this->createMock(QueryBuilder::class);
+        $queryBuilder->method('select')->willReturnSelf();
+        $queryBuilder->method('from')->willReturnSelf();
+        $queryBuilder->method('where')->willReturnSelf();
+        $queryBuilder->method('orderBy')->willReturnSelf();
+
+        // Verify andWhere is called for each filter
+        $queryBuilder->expects($this->atLeast(4))
+            ->method('andWhere')
+            ->willReturnSelf();
+
+        // Verify setParameter is called with expected parameters
+        $capturedParams = [];
+        $queryBuilder->method('setParameter')
+            ->willReturnCallback(static function (string $key, mixed $value) use ($queryBuilder, &$capturedParams) {
+                $capturedParams[$key] = $value;
+
+                return $queryBuilder;
+            });
+
+        // Verify pagination
+        $queryBuilder->expects($this->once())
+            ->method('setMaxResults')
+            ->with(50)
+            ->willReturnSelf();
+
+        $queryBuilder->expects($this->once())
+            ->method('setFirstResult')
+            ->with(10)
+            ->willReturnSelf();
+
+        $result = $this->createMock(Result::class);
+        $result->method('fetchAllAssociative')->willReturn([]);
+        $queryBuilder->method('executeQuery')->willReturn($result);
+
+        $this->connection->method('createQueryBuilder')->willReturn($queryBuilder);
+
+        $this->repository->findByUser(
+            $userId,
+            $tenantId,
+            $from,
+            $to,
+            'ConnexionReussie',
+            50,
+            10,
+        );
+
+        // Verify the parameters were captured
+        $this->assertArrayHasKey('user_id', $capturedParams);
+        $this->assertArrayHasKey('tenant_id', $capturedParams);
+        $this->assertArrayHasKey('from', $capturedParams);
+        $this->assertArrayHasKey('to', $capturedParams);
+        $this->assertArrayHasKey('event_type', $capturedParams);
+        $this->assertSame('ConnexionReussie', $capturedParams['event_type']);
+    }
+
+    public function testFindByResourceReturnsResults(): void
+    {
+        $aggregateId = Uuid::uuid4();
+        $tenantId = TenantId::generate();
+
+        $rows = [$this->createRowData()];
+
+        $queryBuilder = $this->createQueryBuilderMock($rows);
+        $this->connection->method('createQueryBuilder')->willReturn($queryBuilder);
+
+        $result = $this->repository->findByResource('Note', $aggregateId, $tenantId);
+
+        $this->assertCount(1, $result);
+    }
+
+    public function testFindByCorrelationIdReturnsResults(): void
+    {
+        $correlationId = Uuid::uuid4()->toString();
+        $tenantId = TenantId::generate();
+
+        $rows = [$this->createRowData()];
+
+        $queryBuilder = $this->createQueryBuilderMock($rows);
+        $this->connection->method('createQueryBuilder')->willReturn($queryBuilder);
+
+        $result = $this->repository->findByCorrelationId($correlationId, $tenantId);
+
+        $this->assertCount(1, $result);
+    }
+
+    public function testSearchWithAllFilters(): void
+    {
+        $tenantId = TenantId::generate();
+        $from = new DateTimeImmutable('2026-01-01');
+        $to = new DateTimeImmutable('2026-02-01');
+
+        $rows = [$this->createRowData()];
+
+        $queryBuilder = $this->createQueryBuilderMock($rows);
+        $this->connection->method('createQueryBuilder')->willReturn($queryBuilder);
+
+        $result = $this->repository->search(
+            $tenantId,
+            $from,
+            $to,
+            'ConnexionReussie',
+            'User',
+            100,
+            0,
+        );
+
+        $this->assertCount(1, $result);
+    }
+
+    public function testEmptyResultReturnsEmptyArray(): void
+    {
+        $userId = Uuid::uuid4();
+        $tenantId = TenantId::generate();
+
+        $queryBuilder = $this->createQueryBuilderMock([]);
+        $this->connection->method('createQueryBuilder')->willReturn($queryBuilder);
+
+        $result = $this->repository->findByUser($userId, $tenantId);
+
+        $this->assertSame([], $result);
+    }
+
+    /**
+     * @return array<string, mixed>
+     */
+    private function createRowData(): array
+    {
+        return [
+            'id' => Uuid::uuid4()->toString(),
+            'aggregate_type' => 'User',
+            'aggregate_id' => Uuid::uuid4()->toString(),
+            'event_type' => 'ConnexionReussie',
+            'payload' => '{"email_hash":"abc123"}',
+            'metadata' => '{"tenant_id":"tenant-1","user_id":"user-1"}',
+            'occurred_at' => '2026-02-03T10:30:00+00:00',
+            'sequence_number' => '1',
+        ];
+    }
+
+    /**
+     * @param list<array<string, mixed>> $rows
+     */
+    private function createQueryBuilderMock(array $rows): QueryBuilder&MockObject
+    {
+        $queryBuilder = $this->createMock(QueryBuilder::class);
+        $queryBuilder->method('select')->willReturnSelf();
+        $queryBuilder->method('from')->willReturnSelf();
+        $queryBuilder->method('where')->willReturnSelf();
+        $queryBuilder->method('andWhere')->willReturnSelf();
+        $queryBuilder->method('setParameter')->willReturnSelf();
+        $queryBuilder->method('orderBy')->willReturnSelf();
+        $queryBuilder->method('setMaxResults')->willReturnSelf();
+        $queryBuilder->method('setFirstResult')->willReturnSelf();
+
+        $result = $this->createMock(Result::class);
+        $result->method('fetchAllAssociative')->willReturn($rows);
+        $queryBuilder->method('executeQuery')->willReturn($result);
+
+        return $queryBuilder;
+    }
+}
diff --git a/backend/tests/Unit/Shared/Infrastructure/Audit/AuditLoggerTest.php b/backend/tests/Unit/Shared/Infrastructure/Audit/AuditLoggerTest.php
new file mode 100644
index 0000000..1eb4aa7
--- /dev/null
+++ b/backend/tests/Unit/Shared/Infrastructure/Audit/AuditLoggerTest.php
@@ -0,0 +1,354 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Shared\Infrastructure\Audit;
+
+use App\Shared\Domain\Clock;
+use App\Shared\Domain\CorrelationId;
+use App\Shared\Domain\Tenant\TenantId;
+use App\Shared\Infrastructure\Audit\AuditLogger;
+use App\Shared\Infrastructure\Audit\CorrelationIdHolder;
+use App\Shared\Infrastructure\Tenant\TenantConfig;
+use App\Shared\Infrastructure\Tenant\TenantContext;
+use App\Shared\Infrastructure\Tenant\TenantId as InfrastructureTenantId;
+use DateTimeImmutable;
+use Doctrine\DBAL\Connection;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
+use Ramsey\Uuid\Uuid;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\RequestStack;
+use Symfony\Component\Security\Core\Authentication\Token\Storage\TokenStorageInterface;
+
+/**
+ * @see Story 1.7 - T2: AuditLogger Service
+ */
+final class AuditLoggerTest extends TestCase
+{
+    private Connection&MockObject $connection;
+    private TenantContext $tenantContext;
+    private TokenStorageInterface&MockObject $tokenStorage;
+    private RequestStack $requestStack;
+    private Clock&MockObject $clock;
+    private AuditLogger $auditLogger;
+
+    protected function setUp(): void
+    {
+        $this->connection = $this->createMock(Connection::class);
+        $this->tenantContext = new TenantContext();
+        $this->tokenStorage = $this->createMock(TokenStorageInterface::class);
+        $this->requestStack = new RequestStack();
+        $this->clock = $this->createMock(Clock::class);
+
+        $this->auditLogger = new AuditLogger(
+            $this->connection,
+            $this->tenantContext,
+            $this->tokenStorage,
+            $this->requestStack,
+            $this->clock,
+            'test-secret',
+        );
+
+        CorrelationIdHolder::clear();
+    }
+
+    protected function tearDown(): void
+    {
+        CorrelationIdHolder::clear();
+        $this->tenantContext->clear();
+    }
+
+    public function testLogAuthenticationInsertsIntoDatabase(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:30:00');
+        $this->clock->method('now')->willReturn($now);
+        $this->tokenStorage->method('getToken')->willReturn(null);
+
+        $userId = Uuid::uuid4();
+
+        $this->connection->expects($this->once())
+            ->method('insert')
+            ->with(
+                'audit_log',
+                $this->callback(static function (array $data) use ($userId): bool {
+                    return $data['aggregate_type'] === 'User'
+                        && $data['aggregate_id'] === $userId->toString()
+                        && $data['event_type'] === 'TestEvent'
+                        && $data['payload']['test_key'] === 'test_value';
+                }),
+                $this->anything(),
+            );
+
+        $this->auditLogger->logAuthentication('TestEvent', $userId, ['test_key' => 'test_value']);
+    }
+
+    public function testLogAuthenticationWithNullUserIdSetsNullAggregateId(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:30:00');
+        $this->clock->method('now')->willReturn($now);
+        $this->tokenStorage->method('getToken')->willReturn(null);
+
+        $this->connection->expects($this->once())
+            ->method('insert')
+            ->with(
+                'audit_log',
+                $this->callback(static fn (array $data): bool => $data['aggregate_id'] === null),
+                $this->anything(),
+            );
+
+        $this->auditLogger->logAuthentication('FailedLogin', null, []);
+    }
+
+    public function testLogDataChangeIncludesOldAndNewValues(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:30:00');
+        $this->clock->method('now')->willReturn($now);
+        $this->tokenStorage->method('getToken')->willReturn(null);
+
+        $aggregateId = Uuid::uuid4();
+
+        $this->connection->expects($this->once())
+            ->method('insert')
+            ->with(
+                'audit_log',
+                $this->callback(static function (array $data) use ($aggregateId): bool {
+                    $payload = $data['payload'];
+
+                    return $data['aggregate_type'] === 'Note'
+                        && $data['aggregate_id'] === $aggregateId->toString()
+                        && $data['event_type'] === 'NoteModified'
+                        && $payload['old_values']['value'] === 12.5
+                        && $payload['new_values']['value'] === 14.0
+                        && $payload['reason'] === 'Correction';
+                }),
+                $this->anything(),
+            );
+
+        $this->auditLogger->logDataChange(
+            'Note',
+            $aggregateId,
+            'NoteModified',
+            ['value' => 12.5],
+            ['value' => 14.0],
+            'Correction',
+        );
+    }
+
+    public function testLogExportIncludesExportDetails(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:30:00');
+        $this->clock->method('now')->willReturn($now);
+        $this->tokenStorage->method('getToken')->willReturn(null);
+
+        $this->connection->expects($this->once())
+            ->method('insert')
+            ->with(
+                'audit_log',
+                $this->callback(static function (array $data): bool {
+                    $payload = $data['payload'];
+
+                    return $data['aggregate_type'] === 'Export'
+                        && $data['event_type'] === 'ExportGenerated'
+                        && $payload['export_type'] === 'CSV'
+                        && $payload['record_count'] === 150
+                        && $payload['target'] === 'students_list';
+                }),
+                $this->anything(),
+            );
+
+        $this->auditLogger->logExport('CSV', 150, 'students_list');
+    }
+
+    public function testLogAccessIncludesResourceAndContext(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:30:00');
+        $this->clock->method('now')->willReturn($now);
+        $this->tokenStorage->method('getToken')->willReturn(null);
+
+        $resourceId = Uuid::uuid4();
+
+        $this->connection->expects($this->once())
+            ->method('insert')
+            ->with(
+                'audit_log',
+                $this->callback(static function (array $data) use ($resourceId): bool {
+                    $payload = $data['payload'];
+
+                    return $data['aggregate_type'] === 'Student'
+                        && $data['aggregate_id'] === $resourceId->toString()
+                        && $data['event_type'] === 'ResourceAccessed'
+                        && $payload['screen'] === 'profile'
+                        && $payload['action'] === 'view';
+                }),
+                $this->anything(),
+            );
+
+        $this->auditLogger->logAccess('Student', $resourceId, ['screen' => 'profile', 'action' => 'view']);
+    }
+
+    public function testMetadataIncludesTenantIdWhenAvailable(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:30:00');
+        $this->clock->method('now')->willReturn($now);
+        $this->tokenStorage->method('getToken')->willReturn(null);
+
+        $tenantId = TenantId::generate();
+        $this->setCurrentTenant($tenantId);
+
+        $this->connection->expects($this->once())
+            ->method('insert')
+            ->with(
+                'audit_log',
+                $this->callback(static function (array $data) use ($tenantId): bool {
+                    $metadata = $data['metadata'];
+
+                    return $metadata['tenant_id'] === (string) $tenantId;
+                }),
+                $this->anything(),
+            );
+
+        $this->auditLogger->logAuthentication('Test', null, []);
+    }
+
+    public function testMetadataIncludesCorrelationIdWhenSet(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:30:00');
+        $this->clock->method('now')->willReturn($now);
+        $this->tokenStorage->method('getToken')->willReturn(null);
+
+        $correlationId = CorrelationId::generate();
+        CorrelationIdHolder::set($correlationId);
+
+        $this->connection->expects($this->once())
+            ->method('insert')
+            ->with(
+                'audit_log',
+                $this->callback(static function (array $data) use ($correlationId): bool {
+                    $metadata = $data['metadata'];
+
+                    return $metadata['correlation_id'] === $correlationId->value();
+                }),
+                $this->anything(),
+            );
+
+        $this->auditLogger->logAuthentication('Test', null, []);
+    }
+
+    public function testMetadataIncludesHashedIpFromRequest(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:30:00');
+        $this->clock->method('now')->willReturn($now);
+        $this->tokenStorage->method('getToken')->willReturn(null);
+
+        $request = Request::create('/test');
+        $request->server->set('REMOTE_ADDR', '192.168.1.100');
+        $this->requestStack->push($request);
+
+        $expectedIpHash = hash('sha256', '192.168.1.100test-secret');
+
+        $this->connection->expects($this->once())
+            ->method('insert')
+            ->with(
+                'audit_log',
+                $this->callback(static function (array $data) use ($expectedIpHash): bool {
+                    $metadata = $data['metadata'];
+
+                    return $metadata['ip_hash'] === $expectedIpHash;
+                }),
+                $this->anything(),
+            );
+
+        $this->auditLogger->logAuthentication('Test', null, []);
+    }
+
+    public function testMetadataIncludesUserAgentHash(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:30:00');
+        $this->clock->method('now')->willReturn($now);
+        $this->tokenStorage->method('getToken')->willReturn(null);
+
+        $request = Request::create('/test');
+        $request->headers->set('User-Agent', 'Mozilla/5.0 TestBrowser');
+        $this->requestStack->push($request);
+
+        $expectedUaHash = hash('sha256', 'Mozilla/5.0 TestBrowser');
+
+        $this->connection->expects($this->once())
+            ->method('insert')
+            ->with(
+                'audit_log',
+                $this->callback(static function (array $data) use ($expectedUaHash): bool {
+                    $metadata = $data['metadata'];
+
+                    return $metadata['user_agent_hash'] === $expectedUaHash;
+                }),
+                $this->anything(),
+            );
+
+        $this->auditLogger->logAuthentication('Test', null, []);
+    }
+
+    public function testLogAuthenticationWithTenantIdOverride(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:30:00');
+        $this->clock->method('now')->willReturn($now);
+        $this->tokenStorage->method('getToken')->willReturn(null);
+
+        $overrideTenantId = 'override-tenant-uuid-1234';
+
+        $this->connection->expects($this->once())
+            ->method('insert')
+            ->with(
+                'audit_log',
+                $this->callback(static function (array $data) use ($overrideTenantId): bool {
+                    $metadata = $data['metadata'];
+
+                    return $metadata['tenant_id'] === $overrideTenantId;
+                }),
+                $this->anything(),
+            );
+
+        // No TenantContext set, but override should be used
+        $this->auditLogger->logAuthentication('Test', null, [], $overrideTenantId);
+    }
+
+    public function testTenantIdOverrideTakesPrecedenceOverContext(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:30:00');
+        $this->clock->method('now')->willReturn($now);
+        $this->tokenStorage->method('getToken')->willReturn(null);
+
+        // Set a tenant in context
+        $contextTenantId = TenantId::generate();
+        $this->setCurrentTenant($contextTenantId);
+
+        // But use a different override
+        $overrideTenantId = 'override-tenant-uuid-5678';
+
+        $this->connection->expects($this->once())
+            ->method('insert')
+            ->with(
+                'audit_log',
+                $this->callback(static function (array $data) use ($overrideTenantId): bool {
+                    $metadata = $data['metadata'];
+
+                    // Override should take precedence over context
+                    return $metadata['tenant_id'] === $overrideTenantId;
+                }),
+                $this->anything(),
+            );
+
+        $this->auditLogger->logAuthentication('Test', null, [], $overrideTenantId);
+    }
+
+    private function setCurrentTenant(TenantId $tenantId): void
+    {
+        $config = new TenantConfig(
+            tenantId: InfrastructureTenantId::fromString((string) $tenantId),
+            subdomain: 'test-tenant',
+            databaseUrl: 'postgresql://user:pass@localhost:5432/classeo_test',
+        );
+        $this->tenantContext->setCurrentTenant($config);
+    }
+}
diff --git a/backend/tests/Unit/Shared/Infrastructure/Audit/CorrelationIdHolderTest.php b/backend/tests/Unit/Shared/Infrastructure/Audit/CorrelationIdHolderTest.php
new file mode 100644
index 0000000..6e690a2
--- /dev/null
+++ b/backend/tests/Unit/Shared/Infrastructure/Audit/CorrelationIdHolderTest.php
@@ -0,0 +1,87 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Shared\Infrastructure\Audit;
+
+use App\Shared\Domain\CorrelationId;
+use App\Shared\Infrastructure\Audit\CorrelationIdHolder;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * @see Story 1.7 - T3: Correlation ID
+ */
+final class CorrelationIdHolderTest extends TestCase
+{
+    protected function tearDown(): void
+    {
+        CorrelationIdHolder::clear();
+    }
+
+    public function testInitiallyReturnsNull(): void
+    {
+        CorrelationIdHolder::clear();
+
+        $this->assertNull(CorrelationIdHolder::get());
+    }
+
+    public function testSetAndGetCorrelationId(): void
+    {
+        $correlationId = CorrelationId::generate();
+
+        CorrelationIdHolder::set($correlationId);
+
+        $this->assertSame($correlationId, CorrelationIdHolder::get());
+    }
+
+    public function testClearRemovesCorrelationId(): void
+    {
+        CorrelationIdHolder::set(CorrelationId::generate());
+
+        CorrelationIdHolder::clear();
+
+        $this->assertNull(CorrelationIdHolder::get());
+    }
+
+    public function testSetOverwritesPreviousValue(): void
+    {
+        $first = CorrelationId::generate();
+        $second = CorrelationId::generate();
+
+        CorrelationIdHolder::set($first);
+        CorrelationIdHolder::set($second);
+
+        $this->assertSame($second, CorrelationIdHolder::get());
+    }
+
+    public function testGetOrGenerateReturnsExistingId(): void
+    {
+        $existing = CorrelationId::generate();
+        CorrelationIdHolder::set($existing);
+
+        $result = CorrelationIdHolder::getOrGenerate();
+
+        $this->assertSame($existing, $result);
+    }
+
+    public function testGetOrGenerateCreatesNewIdWhenNoneSet(): void
+    {
+        CorrelationIdHolder::clear();
+
+        $result = CorrelationIdHolder::getOrGenerate();
+
+        $this->assertNotNull($result);
+        $this->assertInstanceOf(CorrelationId::class, $result);
+    }
+
+    public function testGetOrGenerateStoresGeneratedId(): void
+    {
+        CorrelationIdHolder::clear();
+
+        $first = CorrelationIdHolder::getOrGenerate();
+        $second = CorrelationIdHolder::getOrGenerate();
+
+        // Should return the same generated ID, not create a new one each time
+        $this->assertSame($first, $second);
+    }
+}
diff --git a/backend/tests/Unit/Shared/Infrastructure/Audit/CorrelationIdMiddlewareTest.php b/backend/tests/Unit/Shared/Infrastructure/Audit/CorrelationIdMiddlewareTest.php
new file mode 100644
index 0000000..039eadd
--- /dev/null
+++ b/backend/tests/Unit/Shared/Infrastructure/Audit/CorrelationIdMiddlewareTest.php
@@ -0,0 +1,188 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Shared\Infrastructure\Audit;
+
+use App\Shared\Domain\CorrelationId;
+use App\Shared\Infrastructure\Audit\CorrelationIdHolder;
+use App\Shared\Infrastructure\Middleware\CorrelationIdMiddleware;
+use PHPUnit\Framework\TestCase;
+use Ramsey\Uuid\Uuid;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\Event\RequestEvent;
+use Symfony\Component\HttpKernel\Event\ResponseEvent;
+use Symfony\Component\HttpKernel\Event\TerminateEvent;
+use Symfony\Component\HttpKernel\HttpKernelInterface;
+
+/**
+ * @see Story 1.7 - T3: Correlation ID
+ */
+final class CorrelationIdMiddlewareTest extends TestCase
+{
+    private CorrelationIdMiddleware $middleware;
+
+    protected function setUp(): void
+    {
+        $this->middleware = new CorrelationIdMiddleware();
+        CorrelationIdHolder::clear();
+    }
+
+    protected function tearDown(): void
+    {
+        CorrelationIdHolder::clear();
+    }
+
+    public function testGeneratesCorrelationIdWhenHeaderMissing(): void
+    {
+        $request = Request::create('/test');
+        $event = $this->createRequestEvent($request, true);
+
+        $this->middleware->onKernelRequest($event);
+
+        $correlationId = CorrelationIdHolder::get();
+        $this->assertNotNull($correlationId);
+        $this->assertTrue(Uuid::isValid($correlationId->value()));
+    }
+
+    public function testUsesExistingCorrelationIdFromHeader(): void
+    {
+        $existingId = '550e8400-e29b-41d4-a716-446655440000';
+        $request = Request::create('/test');
+        $request->headers->set('X-Correlation-Id', $existingId);
+        $event = $this->createRequestEvent($request, true);
+
+        $this->middleware->onKernelRequest($event);
+
+        $correlationId = CorrelationIdHolder::get();
+        $this->assertNotNull($correlationId);
+        $this->assertSame($existingId, $correlationId->value());
+    }
+
+    public function testGeneratesNewIdWhenHeaderContainsInvalidUuid(): void
+    {
+        $request = Request::create('/test');
+        $request->headers->set('X-Correlation-Id', 'not-a-valid-uuid');
+        $event = $this->createRequestEvent($request, true);
+
+        $this->middleware->onKernelRequest($event);
+
+        $correlationId = CorrelationIdHolder::get();
+        $this->assertNotNull($correlationId);
+        // Should have generated a new valid UUID, not kept the invalid one
+        $this->assertTrue(Uuid::isValid($correlationId->value()));
+        $this->assertNotSame('not-a-valid-uuid', $correlationId->value());
+    }
+
+    public function testStoresCorrelationIdInRequestAttributes(): void
+    {
+        $request = Request::create('/test');
+        $event = $this->createRequestEvent($request, true);
+
+        $this->middleware->onKernelRequest($event);
+
+        $this->assertInstanceOf(CorrelationId::class, $request->attributes->get('correlation_id'));
+    }
+
+    public function testIgnoresSubRequests(): void
+    {
+        $request = Request::create('/test');
+        $event = $this->createRequestEvent($request, false);
+
+        $this->middleware->onKernelRequest($event);
+
+        $this->assertNull(CorrelationIdHolder::get());
+    }
+
+    public function testAddsCorrelationIdHeaderToResponse(): void
+    {
+        $correlationId = CorrelationId::generate();
+        CorrelationIdHolder::set($correlationId);
+
+        $request = Request::create('/test');
+        $response = new Response();
+        $event = $this->createResponseEvent($request, $response, true);
+
+        $this->middleware->onKernelResponse($event);
+
+        $this->assertSame(
+            $correlationId->value(),
+            $response->headers->get('X-Correlation-Id'),
+        );
+    }
+
+    public function testDoesNotAddHeaderToSubRequestResponse(): void
+    {
+        $correlationId = CorrelationId::generate();
+        CorrelationIdHolder::set($correlationId);
+
+        $request = Request::create('/test');
+        $response = new Response();
+        $event = $this->createResponseEvent($request, $response, false);
+
+        $this->middleware->onKernelResponse($event);
+
+        $this->assertNull($response->headers->get('X-Correlation-Id'));
+    }
+
+    public function testClearsCorrelationIdOnTerminate(): void
+    {
+        CorrelationIdHolder::set(CorrelationId::generate());
+
+        $request = Request::create('/test');
+        $response = new Response();
+        $event = $this->createTerminateEvent($request, $response);
+
+        $this->middleware->onKernelTerminate($event);
+
+        $this->assertNull(CorrelationIdHolder::get());
+    }
+
+    public function testDefensiveClearOnNewRequest(): void
+    {
+        // Simulate a stale correlation ID from a previous request that didn't clean up
+        $staleId = CorrelationId::generate();
+        CorrelationIdHolder::set($staleId);
+
+        $request = Request::create('/test');
+        $event = $this->createRequestEvent($request, true);
+
+        $this->middleware->onKernelRequest($event);
+
+        // Should have a NEW correlation ID, not the stale one
+        $newId = CorrelationIdHolder::get();
+        $this->assertNotNull($newId);
+        $this->assertNotSame($staleId->value(), $newId->value());
+    }
+
+    private function createRequestEvent(Request $request, bool $isMainRequest): RequestEvent
+    {
+        $kernel = $this->createMock(HttpKernelInterface::class);
+
+        return new RequestEvent(
+            $kernel,
+            $request,
+            $isMainRequest ? HttpKernelInterface::MAIN_REQUEST : HttpKernelInterface::SUB_REQUEST,
+        );
+    }
+
+    private function createResponseEvent(Request $request, Response $response, bool $isMainRequest): ResponseEvent
+    {
+        $kernel = $this->createMock(HttpKernelInterface::class);
+
+        return new ResponseEvent(
+            $kernel,
+            $request,
+            $isMainRequest ? HttpKernelInterface::MAIN_REQUEST : HttpKernelInterface::SUB_REQUEST,
+            $response,
+        );
+    }
+
+    private function createTerminateEvent(Request $request, Response $response): TerminateEvent
+    {
+        $kernel = $this->createMock(HttpKernelInterface::class);
+
+        return new TerminateEvent($kernel, $request, $response);
+    }
+}
diff --git a/backend/tests/Unit/Shared/Infrastructure/Audit/Handler/AuditAuthenticationHandlerTest.php b/backend/tests/Unit/Shared/Infrastructure/Audit/Handler/AuditAuthenticationHandlerTest.php
new file mode 100644
index 0000000..ad775ee
--- /dev/null
+++ b/backend/tests/Unit/Shared/Infrastructure/Audit/Handler/AuditAuthenticationHandlerTest.php
@@ -0,0 +1,200 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Shared\Infrastructure\Audit\Handler;
+
+use App\Administration\Domain\Event\CompteBloqueTemporairement;
+use App\Administration\Domain\Event\ConnexionEchouee;
+use App\Administration\Domain\Event\ConnexionReussie;
+use App\Administration\Domain\Event\MotDePasseChange;
+use App\Shared\Application\Port\AuditLogger;
+use App\Shared\Domain\Tenant\TenantId;
+use App\Shared\Infrastructure\Audit\Handler\AuditAuthenticationHandler;
+use DateTimeImmutable;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
+use Ramsey\Uuid\Uuid;
+
+/**
+ * @see Story 1.7 - T4: Listeners Authentification
+ */
+final class AuditAuthenticationHandlerTest extends TestCase
+{
+    private AuditLogger&MockObject $auditLogger;
+    private AuditAuthenticationHandler $handler;
+
+    protected function setUp(): void
+    {
+        $this->auditLogger = $this->createMock(AuditLogger::class);
+        $this->handler = new AuditAuthenticationHandler(
+            $this->auditLogger,
+            'test-secret',
+        );
+    }
+
+    public function testHandleConnexionReussieLogsSuccessfulLogin(): void
+    {
+        $userId = Uuid::uuid4()->toString();
+        $event = new ConnexionReussie(
+            userId: $userId,
+            email: 'user@example.com',
+            tenantId: TenantId::generate(),
+            ipAddress: '192.168.1.1',
+            userAgent: 'Mozilla/5.0',
+            occurredOn: new DateTimeImmutable(),
+        );
+
+        $this->auditLogger->expects($this->once())
+            ->method('logAuthentication')
+            ->with(
+                $this->equalTo('ConnexionReussie'),
+                $this->callback(static fn ($uuid) => $uuid->toString() === $userId),
+                $this->callback(static fn ($payload) => $payload['result'] === 'success'
+                    && $payload['method'] === 'password'
+                    && isset($payload['email_hash'])
+                ),
+            );
+
+        $this->handler->handleConnexionReussie($event);
+    }
+
+    public function testHandleConnexionEchoueeLogsFailedLogin(): void
+    {
+        $tenantId = TenantId::generate();
+        $event = new ConnexionEchouee(
+            email: 'user@example.com',
+            tenantId: $tenantId,
+            ipAddress: '192.168.1.1',
+            userAgent: 'Mozilla/5.0',
+            reason: 'invalid_credentials',
+            occurredOn: new DateTimeImmutable(),
+        );
+
+        $this->auditLogger->expects($this->once())
+            ->method('logAuthentication')
+            ->with(
+                $this->equalTo('ConnexionEchouee'),
+                $this->isNull(),
+                $this->callback(static fn ($payload) => $payload['result'] === 'failure'
+                    && $payload['reason'] === 'invalid_credentials'
+                    && isset($payload['email_hash'])
+                ),
+                $this->equalTo((string) $tenantId),
+            );
+
+        $this->handler->handleConnexionEchouee($event);
+    }
+
+    public function testHandleCompteBloqueTemporairementLogsLockout(): void
+    {
+        $tenantId = TenantId::generate();
+        $event = new CompteBloqueTemporairement(
+            email: 'user@example.com',
+            tenantId: $tenantId,
+            ipAddress: '192.168.1.1',
+            userAgent: 'Mozilla/5.0',
+            blockedForSeconds: 300,
+            failedAttempts: 5,
+            occurredOn: new DateTimeImmutable(),
+        );
+
+        $this->auditLogger->expects($this->once())
+            ->method('logAuthentication')
+            ->with(
+                $this->equalTo('CompteBloqueTemporairement'),
+                $this->isNull(),
+                $this->callback(static fn ($payload) => $payload['blocked_for_seconds'] === 300
+                    && $payload['failed_attempts'] === 5
+                    && isset($payload['email_hash'])
+                ),
+                $this->equalTo((string) $tenantId),
+            );
+
+        $this->handler->handleCompteBloqueTemporairement($event);
+    }
+
+    public function testHandleMotDePasseChangeLogsPasswordChange(): void
+    {
+        $userId = Uuid::uuid4()->toString();
+        $event = new MotDePasseChange(
+            userId: $userId,
+            email: 'user@example.com',
+            tenantId: TenantId::generate(),
+            occurredOn: new DateTimeImmutable(),
+        );
+
+        $this->auditLogger->expects($this->once())
+            ->method('logAuthentication')
+            ->with(
+                $this->equalTo('MotDePasseChange'),
+                $this->callback(static fn ($uuid) => $uuid->toString() === $userId),
+                $this->callback(static fn ($payload) => isset($payload['email_hash'])),
+            );
+
+        $this->handler->handleMotDePasseChange($event);
+    }
+
+    public function testEmailIsHashedConsistently(): void
+    {
+        $email = 'user@example.com';
+        $expectedHash = hash('sha256', strtolower($email) . 'test-secret');
+
+        $capturedPayload = null;
+        $this->auditLogger->expects($this->once())
+            ->method('logAuthentication')
+            ->willReturnCallback(static function ($eventType, $userId, $payload) use (&$capturedPayload) {
+                $capturedPayload = $payload;
+            });
+
+        $event = new ConnexionReussie(
+            userId: Uuid::uuid4()->toString(),
+            email: $email,
+            tenantId: TenantId::generate(),
+            ipAddress: '192.168.1.1',
+            userAgent: 'Mozilla/5.0',
+            occurredOn: new DateTimeImmutable(),
+        );
+
+        $this->handler->handleConnexionReussie($event);
+
+        $this->assertSame($expectedHash, $capturedPayload['email_hash']);
+    }
+
+    public function testEmailHashIsCaseInsensitive(): void
+    {
+        $lowerEmail = 'user@example.com';
+        $upperEmail = 'USER@EXAMPLE.COM';
+        $expectedHash = hash('sha256', strtolower($lowerEmail) . 'test-secret');
+
+        $payloads = [];
+        $this->auditLogger->expects($this->exactly(2))
+            ->method('logAuthentication')
+            ->willReturnCallback(static function ($eventType, $userId, $payload) use (&$payloads) {
+                $payloads[] = $payload;
+            });
+
+        $event1 = new ConnexionReussie(
+            userId: Uuid::uuid4()->toString(),
+            email: $lowerEmail,
+            tenantId: TenantId::generate(),
+            ipAddress: '192.168.1.1',
+            userAgent: 'Mozilla/5.0',
+            occurredOn: new DateTimeImmutable(),
+        );
+
+        $event2 = new ConnexionReussie(
+            userId: Uuid::uuid4()->toString(),
+            email: $upperEmail,
+            tenantId: TenantId::generate(),
+            ipAddress: '192.168.1.1',
+            userAgent: 'Mozilla/5.0',
+            occurredOn: new DateTimeImmutable(),
+        );
+
+        $this->handler->handleConnexionReussie($event1);
+        $this->handler->handleConnexionReussie($event2);
+
+        $this->assertSame($payloads[0]['email_hash'], $payloads[1]['email_hash']);
+    }
+}
diff --git a/backend/tests/Unit/Shared/Infrastructure/Console/ArchiveAuditLogsCommandTest.php b/backend/tests/Unit/Shared/Infrastructure/Console/ArchiveAuditLogsCommandTest.php
new file mode 100644
index 0000000..2873b27
--- /dev/null
+++ b/backend/tests/Unit/Shared/Infrastructure/Console/ArchiveAuditLogsCommandTest.php
@@ -0,0 +1,224 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Shared\Infrastructure\Console;
+
+use App\Shared\Domain\Clock;
+use App\Shared\Infrastructure\Console\ArchiveAuditLogsCommand;
+use DateTimeImmutable;
+use Doctrine\DBAL\Connection;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Tester\CommandTester;
+
+/**
+ * @see Story 1.7 - T8: Archivage
+ */
+final class ArchiveAuditLogsCommandTest extends TestCase
+{
+    private Connection&MockObject $connection;
+    private Clock&MockObject $clock;
+    private ArchiveAuditLogsCommand $command;
+    private CommandTester $commandTester;
+
+    protected function setUp(): void
+    {
+        $this->connection = $this->createMock(Connection::class);
+        $this->clock = $this->createMock(Clock::class);
+
+        $this->command = new ArchiveAuditLogsCommand(
+            $this->connection,
+            $this->clock,
+        );
+
+        $this->commandTester = new CommandTester($this->command);
+    }
+
+    public function testCommandNameIsCorrect(): void
+    {
+        $this->assertSame('app:audit:archive', $this->command->getName());
+    }
+
+    public function testCommandDescription(): void
+    {
+        $this->assertSame(
+            'Archive audit log entries older than 5 years',
+            $this->command->getDescription(),
+        );
+    }
+
+    public function testNoEntriesToArchiveReturnsSuccess(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:00:00');
+        $this->clock->method('now')->willReturn($now);
+
+        $this->connection->method('fetchOne')
+            ->willReturnOnConsecutiveCalls(0); // COUNT returns 0
+
+        $this->commandTester->execute([]);
+
+        $output = $this->commandTester->getDisplay();
+        $this->assertStringContainsString('No entries to archive', $output);
+        $this->assertSame(Command::SUCCESS, $this->commandTester->getStatusCode());
+    }
+
+    public function testDryRunDoesNotCallArchiveFunction(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:00:00');
+        $this->clock->method('now')->willReturn($now);
+
+        $this->connection->expects($this->once())
+            ->method('fetchOne')
+            ->willReturn(100); // 100 entries to archive
+
+        // archive_audit_entries should NOT be called in dry-run mode
+        $this->connection->expects($this->never())
+            ->method('executeStatement');
+
+        $this->commandTester->execute(['--dry-run' => true]);
+
+        $output = $this->commandTester->getDisplay();
+        $this->assertStringContainsString('DRY RUN', $output);
+        $this->assertStringContainsString('Would archive 100 entries', $output);
+        $this->assertSame(Command::SUCCESS, $this->commandTester->getStatusCode());
+    }
+
+    public function testArchivesBatchesUntilComplete(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:00:00');
+        $this->clock->method('now')->willReturn($now);
+
+        // First call: COUNT returns 150
+        // Subsequent calls: archive_audit_entries returns batch counts
+        $this->connection->method('fetchOne')
+            ->willReturnOnConsecutiveCalls(
+                150,    // COUNT query
+                100,    // First batch (full)
+                50,     // Second batch (partial, stops)
+            );
+
+        $this->commandTester->execute(['--batch-size' => '100']);
+
+        $output = $this->commandTester->getDisplay();
+        $this->assertStringContainsString('Successfully archived 150', $output);
+        $this->assertSame(Command::SUCCESS, $this->commandTester->getStatusCode());
+    }
+
+    public function testCustomRetentionYears(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:00:00');
+        $this->clock->method('now')->willReturn($now);
+
+        $this->connection->method('fetchOne')->willReturn(0);
+
+        $this->commandTester->execute(['--retention-years' => '3']);
+
+        $output = $this->commandTester->getDisplay();
+        $this->assertStringContainsString('(3 years retention)', $output);
+    }
+
+    public function testCustomBatchSize(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:00:00');
+        $this->clock->method('now')->willReturn($now);
+
+        // Return 500 entries to archive, then archive in 500-entry batches
+        $this->connection->method('fetchOne')
+            ->willReturnOnConsecutiveCalls(
+                500,    // COUNT
+                500,    // First batch (equal to batch size)
+                0,      // Second batch (none left)
+            );
+
+        $this->commandTester->execute(['--batch-size' => '500']);
+
+        $output = $this->commandTester->getDisplay();
+        $this->assertStringContainsString('Successfully archived 500', $output);
+    }
+
+    public function testShowsProgressBar(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:00:00');
+        $this->clock->method('now')->willReturn($now);
+
+        $this->connection->method('fetchOne')
+            ->willReturnOnConsecutiveCalls(
+                50,     // COUNT
+                50,     // First batch
+            );
+
+        $this->commandTester->execute([]);
+
+        // Progress bar output includes percentage
+        $output = $this->commandTester->getDisplay();
+        $this->assertStringContainsString('Successfully archived 50', $output);
+    }
+
+    public function testCalculatesCutoffDateCorrectly(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:00:00');
+        $this->clock->method('now')->willReturn($now);
+
+        $capturedCutoff = null;
+        $this->connection->method('fetchOne')
+            ->willReturnCallback(static function (string $sql, array $params) use (&$capturedCutoff) {
+                if (str_contains($sql, 'COUNT')) {
+                    $capturedCutoff = $params['cutoff'];
+
+                    return 0;
+                }
+
+                return 0;
+            });
+
+        $this->commandTester->execute(['--retention-years' => '5']);
+
+        // Cutoff should be 5 years before now (2021-02-03)
+        $this->assertNotNull($capturedCutoff);
+        $this->assertStringContainsString('2021-02-03', $capturedCutoff);
+    }
+
+    public function testZeroBatchSizeReturnsFailure(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:00:00');
+        $this->clock->method('now')->willReturn($now);
+
+        $this->commandTester->execute(['--batch-size' => '0']);
+
+        $output = $this->commandTester->getDisplay();
+        $this->assertStringContainsString('Batch size must be a positive integer', $output);
+        $this->assertSame(Command::FAILURE, $this->commandTester->getStatusCode());
+    }
+
+    public function testNegativeBatchSizeReturnsFailure(): void
+    {
+        $now = new DateTimeImmutable('2026-02-03 10:00:00');
+        $this->clock->method('now')->willReturn($now);
+
+        $this->commandTester->execute(['--batch-size' => '-5']);
+
+        $output = $this->commandTester->getDisplay();
+        $this->assertStringContainsString('Batch size must be a positive integer', $output);
+        $this->assertSame(Command::FAILURE, $this->commandTester->getStatusCode());
+    }
+
+    public function testZeroRetentionYearsReturnsFailure(): void
+    {
+        $this->commandTester->execute(['--retention-years' => '0']);
+
+        $output = $this->commandTester->getDisplay();
+        $this->assertStringContainsString('Retention years must be a positive integer', $output);
+        $this->assertSame(Command::FAILURE, $this->commandTester->getStatusCode());
+    }
+
+    public function testNegativeRetentionYearsReturnsFailure(): void
+    {
+        $this->commandTester->execute(['--retention-years' => '-5']);
+
+        $output = $this->commandTester->getDisplay();
+        $this->assertStringContainsString('Retention years must be a positive integer', $output);
+        $this->assertSame(Command::FAILURE, $this->commandTester->getStatusCode());
+    }
+}
diff --git a/backend/tests/Unit/Shared/Infrastructure/Messenger/AddCorrelationIdStampMiddlewareTest.php b/backend/tests/Unit/Shared/Infrastructure/Messenger/AddCorrelationIdStampMiddlewareTest.php
new file mode 100644
index 0000000..426c85f
--- /dev/null
+++ b/backend/tests/Unit/Shared/Infrastructure/Messenger/AddCorrelationIdStampMiddlewareTest.php
@@ -0,0 +1,94 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Shared\Infrastructure\Messenger;
+
+use App\Shared\Domain\CorrelationId;
+use App\Shared\Infrastructure\Audit\CorrelationIdHolder;
+use App\Shared\Infrastructure\Messenger\AddCorrelationIdStampMiddleware;
+use App\Shared\Infrastructure\Messenger\CorrelationIdStamp;
+use PHPUnit\Framework\TestCase;
+use stdClass;
+use Symfony\Component\Messenger\Envelope;
+use Symfony\Component\Messenger\Middleware\MiddlewareInterface;
+use Symfony\Component\Messenger\Middleware\StackInterface;
+
+/**
+ * @see Story 1.7 - T3: Correlation ID
+ */
+final class AddCorrelationIdStampMiddlewareTest extends TestCase
+{
+    private AddCorrelationIdStampMiddleware $middleware;
+
+    protected function setUp(): void
+    {
+        $this->middleware = new AddCorrelationIdStampMiddleware();
+        CorrelationIdHolder::clear();
+    }
+
+    protected function tearDown(): void
+    {
+        CorrelationIdHolder::clear();
+    }
+
+    public function testAddsStampWhenCorrelationIdIsSet(): void
+    {
+        $correlationId = CorrelationId::generate();
+        CorrelationIdHolder::set($correlationId);
+
+        $envelope = new Envelope(new stdClass());
+        $stack = $this->createCapturingStack();
+
+        $result = $this->middleware->handle($envelope, $stack);
+
+        $stamp = $result->last(CorrelationIdStamp::class);
+        $this->assertInstanceOf(CorrelationIdStamp::class, $stamp);
+        $this->assertSame($correlationId->value(), $stamp->correlationId);
+    }
+
+    public function testDoesNotAddStampWhenNoCorrelationId(): void
+    {
+        CorrelationIdHolder::clear();
+
+        $envelope = new Envelope(new stdClass());
+        $stack = $this->createCapturingStack();
+
+        $result = $this->middleware->handle($envelope, $stack);
+
+        $stamp = $result->last(CorrelationIdStamp::class);
+        $this->assertNull($stamp);
+    }
+
+    public function testDoesNotOverwriteExistingStamp(): void
+    {
+        $existingId = '11111111-1111-1111-1111-111111111111';
+        $currentId = CorrelationId::generate();
+        CorrelationIdHolder::set($currentId);
+
+        $envelope = new Envelope(new stdClass(), [new CorrelationIdStamp($existingId)]);
+        $stack = $this->createCapturingStack();
+
+        $result = $this->middleware->handle($envelope, $stack);
+
+        $stamp = $result->last(CorrelationIdStamp::class);
+        $this->assertInstanceOf(CorrelationIdStamp::class, $stamp);
+        // Should keep the existing stamp, not overwrite with current
+        $this->assertSame($existingId, $stamp->correlationId);
+    }
+
+    private function createCapturingStack(): StackInterface
+    {
+        return new class implements StackInterface {
+            public function next(): MiddlewareInterface
+            {
+                return new class implements MiddlewareInterface {
+                    public function handle(Envelope $envelope, StackInterface $stack): Envelope
+                    {
+                        return $envelope;
+                    }
+                };
+            }
+        };
+    }
+}
diff --git a/backend/tests/Unit/Shared/Infrastructure/Messenger/CorrelationIdMiddlewareTest.php b/backend/tests/Unit/Shared/Infrastructure/Messenger/CorrelationIdMiddlewareTest.php
new file mode 100644
index 0000000..d47befd
--- /dev/null
+++ b/backend/tests/Unit/Shared/Infrastructure/Messenger/CorrelationIdMiddlewareTest.php
@@ -0,0 +1,212 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Shared\Infrastructure\Messenger;
+
+use App\Shared\Infrastructure\Audit\CorrelationIdHolder;
+use App\Shared\Infrastructure\Messenger\CorrelationIdMiddleware;
+use App\Shared\Infrastructure\Messenger\CorrelationIdStamp;
+use PHPUnit\Framework\TestCase;
+use Ramsey\Uuid\Uuid;
+use RuntimeException;
+use stdClass;
+use Symfony\Component\Messenger\Envelope;
+use Symfony\Component\Messenger\Middleware\MiddlewareInterface;
+use Symfony\Component\Messenger\Middleware\StackInterface;
+
+/**
+ * @see Story 1.7 - T3: Correlation ID
+ */
+final class CorrelationIdMiddlewareTest extends TestCase
+{
+    private CorrelationIdMiddleware $middleware;
+
+    protected function setUp(): void
+    {
+        $this->middleware = new CorrelationIdMiddleware();
+        CorrelationIdHolder::clear();
+    }
+
+    protected function tearDown(): void
+    {
+        CorrelationIdHolder::clear();
+    }
+
+    public function testUsesCorrelationIdFromStampWhenPresent(): void
+    {
+        $expectedId = '550e8400-e29b-41d4-a716-446655440000';
+        $envelope = new Envelope(new stdClass(), [new CorrelationIdStamp($expectedId)]);
+        $stack = $this->createCapturingStack();
+
+        $this->middleware->handle($envelope, $stack);
+
+        // Verify the correlation ID was set during handling
+        $this->assertSame($expectedId, $stack->capturedCorrelationId);
+    }
+
+    public function testGeneratesNewCorrelationIdWhenNoStampAndNoExistingId(): void
+    {
+        // Async worker context: no existing ID, no stamp
+        $envelope = new Envelope(new stdClass());
+        $stack = $this->createCapturingStack();
+
+        $this->middleware->handle($envelope, $stack);
+
+        // Should have generated a valid UUID
+        $this->assertNotNull($stack->capturedCorrelationId);
+        $this->assertTrue(Uuid::isValid($stack->capturedCorrelationId));
+    }
+
+    public function testUsesExistingCorrelationIdDuringSynchronousDispatch(): void
+    {
+        // HTTP context: existing ID is set by HTTP middleware
+        $existingId = '99999999-9999-9999-9999-999999999999';
+        CorrelationIdHolder::set(\App\Shared\Domain\CorrelationId::fromString($existingId));
+
+        $envelope = new Envelope(new stdClass());
+        $stack = $this->createCapturingStack();
+
+        $this->middleware->handle($envelope, $stack);
+
+        // Should use the existing ID, not generate a new one
+        $this->assertSame($existingId, $stack->capturedCorrelationId);
+    }
+
+    public function testDoesNotClearCorrelationIdDuringSynchronousDispatch(): void
+    {
+        // HTTP context: existing ID should be preserved after dispatch
+        $existingId = '99999999-9999-9999-9999-999999999999';
+        CorrelationIdHolder::set(\App\Shared\Domain\CorrelationId::fromString($existingId));
+
+        $envelope = new Envelope(new stdClass());
+        $stack = $this->createPassthroughStack();
+
+        $this->middleware->handle($envelope, $stack);
+
+        // Should NOT be cleared - HTTP middleware handles that
+        $this->assertNotNull(CorrelationIdHolder::get());
+        $this->assertSame($existingId, CorrelationIdHolder::get()?->value());
+    }
+
+    public function testClearsCorrelationIdInAsyncContext(): void
+    {
+        // Async worker context: no existing ID, no stamp
+        $envelope = new Envelope(new stdClass());
+        $stack = $this->createPassthroughStack();
+
+        $this->middleware->handle($envelope, $stack);
+
+        // Should be cleared after handling in async context
+        $this->assertNull(CorrelationIdHolder::get());
+    }
+
+    public function testClearsCorrelationIdWhenStampPresent(): void
+    {
+        // Async worker receiving message from HTTP: has stamp
+        $envelope = new Envelope(new stdClass(), [new CorrelationIdStamp('11111111-1111-1111-1111-111111111111')]);
+        $stack = $this->createPassthroughStack();
+
+        $this->middleware->handle($envelope, $stack);
+
+        // Should be cleared after handling (async context)
+        $this->assertNull(CorrelationIdHolder::get());
+    }
+
+    public function testClearsCorrelationIdEvenOnException(): void
+    {
+        // Async worker context
+        $envelope = new Envelope(new stdClass());
+        $stack = $this->createThrowingStack();
+
+        try {
+            $this->middleware->handle($envelope, $stack);
+            $this->fail('Expected exception to be thrown');
+        } catch (RuntimeException) {
+            // Expected
+        }
+
+        // Should be cleared even after exception in async context
+        $this->assertNull(CorrelationIdHolder::get());
+    }
+
+    public function testDoesNotLeakBetweenMessages(): void
+    {
+        $envelope1 = new Envelope(new stdClass(), [new CorrelationIdStamp('11111111-1111-1111-1111-111111111111')]);
+        $envelope2 = new Envelope(new stdClass(), [new CorrelationIdStamp('22222222-2222-2222-2222-222222222222')]);
+
+        $stack1 = $this->createCapturingStack();
+        $stack2 = $this->createCapturingStack();
+
+        $this->middleware->handle($envelope1, $stack1);
+        $this->middleware->handle($envelope2, $stack2);
+
+        $this->assertSame('11111111-1111-1111-1111-111111111111', $stack1->capturedCorrelationId);
+        $this->assertSame('22222222-2222-2222-2222-222222222222', $stack2->capturedCorrelationId);
+    }
+
+    private function createCapturingStack(): CapturingStack
+    {
+        return new CapturingStack();
+    }
+
+    private function createPassthroughStack(): StackInterface
+    {
+        return new class implements StackInterface {
+            public function next(): MiddlewareInterface
+            {
+                return new class implements MiddlewareInterface {
+                    public function handle(Envelope $envelope, StackInterface $stack): Envelope
+                    {
+                        return $envelope;
+                    }
+                };
+            }
+        };
+    }
+
+    private function createThrowingStack(): StackInterface
+    {
+        return new class implements StackInterface {
+            public function next(): MiddlewareInterface
+            {
+                return new class implements MiddlewareInterface {
+                    public function handle(Envelope $envelope, StackInterface $stack): Envelope
+                    {
+                        throw new RuntimeException('Handler failed');
+                    }
+                };
+            }
+        };
+    }
+}
+
+/**
+ * Stack that captures the correlation ID during handling.
+ */
+final class CapturingStack implements StackInterface
+{
+    public ?string $capturedCorrelationId = null;
+
+    public function next(): MiddlewareInterface
+    {
+        return new CapturingMiddleware($this);
+    }
+}
+
+/**
+ * @internal
+ */
+final class CapturingMiddleware implements MiddlewareInterface
+{
+    public function __construct(private CapturingStack $stack)
+    {
+    }
+
+    public function handle(Envelope $envelope, StackInterface $stack): Envelope
+    {
+        $this->stack->capturedCorrelationId = CorrelationIdHolder::get()?->value();
+
+        return $envelope;
+    }
+}