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>

frontend/components/ui/badge.tsx

@@ -0,0 +1,32 @@
+import * as React from "react";
+import { cva, type VariantProps } from "class-variance-authority";
+import { cn } from "@/lib/utils";
+
+const badgeVariants = cva(
+  "inline-flex items-center rounded-full border px-2.5 py-0.5 text-xs font-semibold transition-colors focus:outline-none focus:ring-2 focus:ring-ring focus:ring-offset-2",
+  {
+    variants: {
+      variant: {
+        default: "border-transparent bg-primary text-primary-foreground hover:bg-primary/80",
+        secondary: "border-transparent bg-secondary text-secondary-foreground hover:bg-secondary/80",
+        destructive: "border-transparent bg-destructive text-destructive-foreground hover:bg-destructive/80",
+        outline: "text-foreground",
+        critique: "border-transparent bg-red-600 text-white",
+        important: "border-transparent bg-orange-500 text-white",
+        modere: "border-transparent bg-yellow-500 text-white",
+        faible: "border-transparent bg-green-500 text-white",
+      },
+    },
+    defaultVariants: { variant: "default" },
+  }
+);
+
+export interface BadgeProps
+  extends React.HTMLAttributes<HTMLDivElement>,
+    VariantProps<typeof badgeVariants> {}
+
+function Badge({ className, variant, ...props }: BadgeProps) {
+  return <div className={cn(badgeVariants({ variant }), className)} {...props} />;
+}
+
+export { Badge, badgeVariants };