feat: Phase 1 — socle backend FastAPI + frontend Next.js

Backend (FastAPI + SQLAlchemy):
- Modèles : User, Client, Audit, Cible, Vulnérabilité, Action
- Auth JWT (register/login/me) avec bcrypt
- Routes CRUD complets : clients, audits, cibles, vulnérabilités, actions
- Schémas Pydantic v2, migrations Alembic configurées
- Rate limiting (slowapi), CORS, structure scanners/reports pour phase 2

Frontend (Next.js 14 App Router):
- shadcn/ui : Button, Input, Card, Badge, Label
- Page login avec gestion token JWT
- Dashboard avec stats temps réel
- Pages Clients (grille) et Audits (liste) avec recherche
- Layout avec sidebar navigation + protection auth
- Dockerfiles multi-stage (backend + frontend standalone)

Infrastructure:
- docker-compose.yml : postgres, redis, backend, frontend
- docker-compose.prod.yml avec labels Traefik
- .env.example complet
- .gitignore mis à jour

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

backend/models/audit.py

@@ -0,0 +1,30 @@
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+from sqlalchemy import String, Integer, Float, ForeignKey, DateTime, Enum as SAEnum
+from datetime import datetime
+import enum
+from backend.models.base import Base, TimestampMixin
+
+
+class AuditStatut(str, enum.Enum):
+    planifie = "planifie"
+    en_cours = "en_cours"
+    termine = "termine"
+    annule = "annule"
+
+
+class Audit(Base, TimestampMixin):
+    __tablename__ = "audits"
+
+    id: Mapped[int] = mapped_column(primary_key=True, index=True)
+    client_id: Mapped[int] = mapped_column(ForeignKey("clients.id"), nullable=False, index=True)
+    nom: Mapped[str] = mapped_column(String(255), nullable=False)
+    statut: Mapped[AuditStatut] = mapped_column(SAEnum(AuditStatut), default=AuditStatut.planifie, nullable=False)
+    date_debut: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
+    date_fin: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
+    score_global: Mapped[float | None] = mapped_column(Float, nullable=True)
+
+    client: Mapped["Client"] = relationship("Client", back_populates="audits")
+    cibles: Mapped[list["Cible"]] = relationship("Cible", back_populates="audit", cascade="all, delete-orphan")
+    vulnerabilites: Mapped[list["Vulnerabilite"]] = relationship(
+        "Vulnerabilite", back_populates="audit", cascade="all, delete-orphan"
+    )