feat: initialiser le projet CVP (Next.js 14 + FastAPI + PostgreSQL)

- Frontend : Next.js 14 App Router, TypeScript strict, Tailwind 3, shadcn/ui, next-intl (fr/en)
- Backend : FastAPI, SQLAlchemy 2 async, Alembic, Pydantic 2, Python 3.11
- Infrastructure : Docker Compose (PostgreSQL 16 + Ollama)
- Tooling : ESLint + Prettier (frontend), Ruff (backend), pytest
- Structure complète des dossiers avec pages et routers placeholder

frontend/.gitignore

@@ -0,0 +1,36 @@
+# See https://help.github.com/articles/ignoring-files/ for more about ignoring files.
+
+# dependencies
+/node_modules
+/.pnp
+.pnp.js
+.yarn/install-state.gz
+
+# testing
+/coverage
+
+# next.js
+/.next/
+/out/
+
+# production
+/build
+
+# misc
+.DS_Store
+*.pem
+
+# debug
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# local env files
+.env*.local
+
+# vercel
+.vercel
+
+# typescript
+*.tsbuildinfo
+next-env.d.ts