refactor : merge Inventory_frontend submodule into frontend/ directory

Merges the full git history of Inventory_frontend into the monorepo
under frontend/. Removes the submodule in favor of a unified repo.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/env.example

@@ -0,0 +1,27 @@
+# Configuration de l'API backend
+NUXT_PUBLIC_API_BASE_URL=http://localhost:3000
+
+# Configuration du serveur de développement
+NUXT_PUBLIC_APP_URL=http://localhost:3001
+NUXT_PUBLIC_APP_NAME="Inventory Management System"
+
+# Configuration de l'environnement
+NODE_ENV=development
+NUXT_APP_ENV=development
+
+# Configuration des fonctionnalités
+NUXT_PUBLIC_ENABLE_DEBUG=true
+NUXT_PUBLIC_ENABLE_ANALYTICS=false
+
+# Configuration de sécurité (optionnel)
+NUXT_PUBLIC_CSRF_TOKEN=your-csrf-token-here
+
+# Configuration des logs
+NUXT_PUBLIC_LOG_LEVEL=debug
+
+# Configuration des timeouts
+NUXT_PUBLIC_API_TIMEOUT=30000
+NUXT_PUBLIC_REQUEST_TIMEOUT=10000 
+
+# Version de l'application (mettre à jour à chaque release)
+NUXT_PUBLIC_APP_VERSION=0.1.0