feat: FASE 1 - Backend Core (modelli, auth, API)

Implementazione completa del backend FastAPI:
- Modelli SQLAlchemy: User, Recipe, RecipeVersion, RecipeTask,
  RecipeSubtask, Measurement, AccessLog, SystemSetting, RecipeVersionAudit
- Schemas Pydantic v2 per tutti i CRUD + statistiche SPC
- Middleware: API Key auth (X-API-Key) con role checking + access logging
- Router: auth, users, recipes, tasks, measurements, files, settings
- Services: auth (bcrypt+secrets), recipe (copy-on-write versioning),
  measurement (auto pass/fail con UTL/UWL/LWL/LTL)
- Alembic env.py con import modelli attivi
- Fix architect review: no double-commit, recipe_id subquery filter,
  user_id in access logs, type annotations corrette

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/main.py

@@ -7,6 +7,14 @@ from fastapi.middleware.cors import CORSMiddleware
 
 from config import settings
 from database import init_db
+from middleware.logging import AccessLogMiddleware
+from routers.auth import router as auth_router
+from routers.users import router as users_router
+from routers.recipes import router as recipes_router
+from routers.tasks import router as tasks_router
+from routers.measurements import router as measurements_router
+from routers.files import router as files_router
+from routers.settings import router as settings_router
 
 
 @asynccontextmanager
@@ -39,6 +47,19 @@ app.add_middleware(
 )
 
 
+# Access logging middleware
+app.add_middleware(AccessLogMiddleware)
+
+# Register routers
+app.include_router(auth_router)
+app.include_router(users_router)
+app.include_router(recipes_router)
+app.include_router(tasks_router)
+app.include_router(measurements_router)
+app.include_router(files_router)
+app.include_router(settings_router)
+
+
 @app.get("/api/health")
 async def health_check() -> dict:
     """Health check endpoint."""