feat: Fase 1 – Fondamenta complete (backend FastAPI + auth + permessi)

- docker-compose.yml: PostgreSQL 16, Redis 7, MinIO, Nginx
- backend FastAPI: struttura monorepo, config pydantic-settings
- modelli SQLAlchemy: tutti i modelli (tenants, users, mailboxes, messages, archival, permissions, labels, audit_log)
- migrazione Alembic 0001: schema completo in pure SQL
- auth API: login JWT, refresh token rotation, logout, 2FA TOTP (setup/verify/disable)
- CRUD utenti: lista, crea, modifica, reset password, soft delete
- permessi granulari (Fase 1-A): mailbox_permissions, assegna/revoca/lista
- CRUD tenant: gestione super-admin
- sicurezza: AES-256-GCM cifratura credenziali IMAP/SMTP, bcrypt password
- RLS PostgreSQL: isolamento multi-tenant per request
- seed sviluppo: tenant demo + admin + operator
- test unit: security (bcrypt, JWT, AES), auth_service
- test integration: auth endpoints, users endpoints
- CI GitHub Actions: lint (ruff), test (pytest), build Docker, security scan
- infra: nginx.conf, redis.conf
- Makefile con comandi make dev/test/migrate/seed

Definition of Done:
✅ Login, refresh token e TOTP funzionanti
✅ make dev porta in piedi tutto lo stack locale
✅ CI configurata

backend/app/dependencies.py

@@ -0,0 +1,117 @@
+"""
+Dependency FastAPI – get_db, get_current_user, require_admin, RLS middleware.
+"""
+
+import uuid
+from typing import Annotated
+
+from fastapi import Depends, Request
+from fastapi.security import HTTPAuthorizationCredentials, HTTPBearer
+from jose import JWTError
+from sqlalchemy import text
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.exceptions import ForbiddenError, TokenInvalidError
+from app.core.security import decode_token
+from app.database import get_db
+from app.models.user import User
+from sqlalchemy import select
+
+security = HTTPBearer()
+
+# ─── Database con RLS ─────────────────────────────────────────────────────────
+
+async def get_db_with_rls(
+    tenant_id: uuid.UUID,
+    db: AsyncSession = Depends(get_db),
+) -> AsyncSession:
+    """
+    Imposta la variabile di sessione PostgreSQL per RLS.
+    Da usare dopo aver estratto il tenant_id dall'utente autenticato.
+    """
+    await db.execute(
+        text("SET LOCAL app.current_tenant_id = :tenant_id"),
+        {"tenant_id": str(tenant_id)},
+    )
+    return db
+
+
+# ─── Utente corrente ──────────────────────────────────────────────────────────
+
+async def get_current_user(
+    credentials: Annotated[HTTPAuthorizationCredentials, Depends(security)],
+    db: AsyncSession = Depends(get_db),
+) -> User:
+    """
+    Estrae e valida il JWT dall'header Authorization: Bearer <token>.
+    Carica l'utente dal DB e imposta RLS.
+    """
+    token = credentials.credentials
+
+    try:
+        payload = decode_token(token)
+    except JWTError:
+        raise TokenInvalidError()
+
+    if payload.get("type") != "access":
+        raise TokenInvalidError()
+
+    user_id_str = payload.get("sub")
+    tenant_id_str = payload.get("tid")
+
+    if not user_id_str or not tenant_id_str:
+        raise TokenInvalidError()
+
+    try:
+        user_id = uuid.UUID(user_id_str)
+        tenant_id = uuid.UUID(tenant_id_str)
+    except ValueError:
+        raise TokenInvalidError()
+
+    # Imposta RLS per questo tenant
+    # SET LOCAL non supporta parametri $1, usiamo text() con valore inline
+    await db.execute(
+        text(f"SET LOCAL app.current_tenant_id = '{tenant_id!s}'")
+    )
+
+    # Carica utente
+    result = await db.execute(
+        select(User).where(User.id == user_id, User.tenant_id == tenant_id)
+    )
+    user = result.scalar_one_or_none()
+
+    if not user:
+        raise TokenInvalidError()
+
+    if not user.is_active:
+        from app.core.exceptions import AccountDisabledError
+        raise AccountDisabledError()
+
+    return user
+
+
+# ─── Role guards ──────────────────────────────────────────────────────────────
+
+async def require_admin(
+    current_user: Annotated[User, Depends(get_current_user)],
+) -> User:
+    """Richiede ruolo admin o super_admin."""
+    if not current_user.is_admin:
+        raise ForbiddenError("Richiesto ruolo amministratore")
+    return current_user
+
+
+async def require_super_admin(
+    current_user: Annotated[User, Depends(get_current_user)],
+) -> User:
+    """Richiede ruolo super_admin."""
+    if not current_user.is_super_admin:
+        raise ForbiddenError("Richiesto ruolo super_admin")
+    return current_user
+
+
+# ─── Tipo annotato per ridurre boilerplate negli endpoint ─────────────────────
+CurrentUser = Annotated[User, Depends(get_current_user)]
+AdminUser = Annotated[User, Depends(require_admin)]
+SuperAdminUser = Annotated[User, Depends(require_super_admin)]
+DB = Annotated[AsyncSession, Depends(get_db)]