feat: Setup projet Classeo avec infrastructure Docker et architecture DDD

Configure l'environnement de développement complet avec Docker Compose,
structure DDD 4 Bounded Contexts, et pipeline CI/CD GitHub Actions.

Corrections compatibilité CI:
- Symfony 8 nécessite monolog-bundle ^4.0 (la v3.x ne supporte que jusqu'à Symfony 7)
- ESLint v9 nécessite flat config (eslint.config.js) - le format .eslintrc.cjs est obsolète

frontend/eslint.config.js

@@ -0,0 +1,96 @@
+import js from '@eslint/js';
+import tseslint from 'typescript-eslint';
+import sveltePlugin from 'eslint-plugin-svelte';
+import svelteParser from 'svelte-eslint-parser';
+import prettier from 'eslint-config-prettier';
+
+export default tseslint.config(
+	// Base JavaScript recommended rules
+	js.configs.recommended,
+
+	// TypeScript recommended rules
+	...tseslint.configs.recommended,
+
+	// Global ignores
+	{
+		ignores: [
+			'.svelte-kit/**',
+			'build/**',
+			'dist/**',
+			'node_modules/**',
+			'*.config.js',
+			'*.config.ts'
+		]
+	},
+
+	// TypeScript files
+	{
+		files: ['**/*.ts'],
+		languageOptions: {
+			parserOptions: {
+				sourceType: 'module',
+				ecmaVersion: 2020
+			},
+			globals: {
+				window: 'readonly',
+				document: 'readonly',
+				console: 'readonly',
+				process: 'readonly',
+				__dirname: 'readonly',
+				__filename: 'readonly',
+				Promise: 'readonly',
+				Set: 'readonly',
+				Map: 'readonly'
+			}
+		},
+		rules: {
+			'@typescript-eslint/no-unused-vars': [
+				'error',
+				{
+					argsIgnorePattern: '^_',
+					varsIgnorePattern: '^_'
+				}
+			],
+			'no-console': ['warn', { allow: ['warn', 'error'] }]
+		}
+	},
+
+	// Svelte files
+	{
+		files: ['**/*.svelte'],
+		languageOptions: {
+			parser: svelteParser,
+			parserOptions: {
+				parser: tseslint.parser,
+				sourceType: 'module',
+				ecmaVersion: 2020,
+				extraFileExtensions: ['.svelte']
+			},
+			globals: {
+				window: 'readonly',
+				document: 'readonly',
+				console: 'readonly',
+				process: 'readonly',
+				Promise: 'readonly',
+				Set: 'readonly',
+				Map: 'readonly'
+			}
+		},
+		plugins: {
+			svelte: sveltePlugin
+		},
+		rules: {
+			...sveltePlugin.configs.recommended.rules,
+			'@typescript-eslint/no-unused-vars': [
+				'error',
+				{
+					argsIgnorePattern: '^_',
+					varsIgnorePattern: '^_'
+				}
+			]
+		}
+	},
+
+	// Prettier (disable conflicting rules)
+	prettier
+);