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/schemas/user.py

@@ -0,0 +1,89 @@
+"""
+Schema Pydantic per utenti.
+"""
+
+import uuid
+from datetime import datetime
+from typing import Literal
+
+from pydantic import BaseModel, EmailStr, Field, field_validator
+
+UserRoleType = Literal["super_admin", "admin", "supervisor", "operator", "readonly"]
+
+
+# ─── Request ──────────────────────────────────────────────────────────────────
+
+class UserCreateRequest(BaseModel):
+    email: EmailStr
+    password: str = Field(min_length=8)
+    full_name: str = Field(min_length=2, max_length=255)
+    role: UserRoleType = "operator"
+
+    @field_validator("password")
+    @classmethod
+    def validate_password(cls, v: str) -> str:
+        if len(v) < 8:
+            raise ValueError("La password deve essere almeno 8 caratteri")
+        if not any(c.isupper() for c in v):
+            raise ValueError("Almeno una lettera maiuscola richiesta")
+        if not any(c.isdigit() for c in v):
+            raise ValueError("Almeno un numero richiesto")
+        return v
+
+    @field_validator("role")
+    @classmethod
+    def validate_role_not_superadmin(cls, v: str) -> str:
+        if v == "super_admin":
+            raise ValueError("Non è possibile creare utenti super_admin via API")
+        return v
+
+
+class UserUpdateRequest(BaseModel):
+    full_name: str | None = Field(default=None, min_length=2, max_length=255)
+    role: UserRoleType | None = None
+    is_active: bool | None = None
+
+    @field_validator("role")
+    @classmethod
+    def validate_role_not_superadmin(cls, v: str | None) -> str | None:
+        if v == "super_admin":
+            raise ValueError("Non è possibile assegnare il ruolo super_admin via API")
+        return v
+
+
+class UserPasswordResetRequest(BaseModel):
+    new_password: str = Field(min_length=8)
+
+    @field_validator("new_password")
+    @classmethod
+    def validate_password(cls, v: str) -> str:
+        if not any(c.isupper() for c in v):
+            raise ValueError("Almeno una lettera maiuscola richiesta")
+        if not any(c.isdigit() for c in v):
+            raise ValueError("Almeno un numero richiesto")
+        return v
+
+
+# ─── Response ─────────────────────────────────────────────────────────────────
+
+class UserResponse(BaseModel):
+    id: uuid.UUID
+    tenant_id: uuid.UUID
+    email: str
+    full_name: str
+    role: str
+    is_active: bool
+    totp_enabled: bool
+    last_login_at: datetime | None
+    created_at: datetime
+    updated_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class UserListResponse(BaseModel):
+    items: list[UserResponse]
+    total: int
+    page: int
+    page_size: int
+    pages: int