feat: sprint 1 — auth + CRUD engagements

Ship the first feature end-to-end on the UI: users log in with JWT,
admins manage user accounts, and any authenticated user (per RBAC)
can create, list, view, edit, and delete engagements.

Backend (Flask + SQLAlchemy + SQLite, 63 pytest)
- User / Engagement models, Alembic 0001 initial schema
- argon2 password hashing, JWT bearer (60-min TTL), @login_required
  and @role_required decorators
- 13 API endpoints under /api/*, including last-admin protection on
  DELETE/PATCH user and JSON 404 on unknown /api/* paths
- `flask create-admin` CLI with duplicate / short-password handling

Frontend (React + Vite + Tailwind + TanStack Query, 20 vitest)
- Inter font bundled locally (no CDN), DESIGN.md tokens in Tailwind
- LoginPage / EngagementsList / EngagementForm / EngagementDetail /
  UsersAdmin pages with role-aware UI
- Layout, ProtectedRoute, StatusBadge, FormField, LoadingState,
  ErrorState, EmptyState, Toast + provider
- Axios client: Bearer interceptor, 401 → purge + /login + "Session
  expirée" toast, 403 → "Accès refusé" toast (declarative <Navigate>
  for already-authed users, Fragment-keyed admin user rows)

Deployment
- Single multistage Dockerfile (node:20-alpine → python:3.12-slim)
- docker/entrypoint.sh runs `flask db upgrade` before `flask run`
- Makefile: build/start/stop/restart/update/logs/create-admin/
  update-mitre/test-{backend,frontend,e2e}/clean
- .env.example documenting MIMIC_JWT_SECRET / MIMIC_DB_PATH / MIMIC_PORT
- SQLite at /data/mimic.sqlite on named volume mimic-data

Acceptance suite (Playwright, 36 tests, all 27 ACs)
- e2e/ scaffold with playwright.config + auth/api fixtures
- One spec per user story (us1-bootstrap through us6-deployment)
- Portable via MIMIC_CONTAINER_CMD / MIMIC_BASE_URL (docker or podman)

Docs
- README.md with quick-start and architecture overview
- CHANGELOG.md updated with Sprint 1 deliverables
- pyrightconfig.json so the Python LSP sees backend/.venv and
  resolves the `backend.app.*` absolute imports

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

backend/tests/test_auth.py

@@ -0,0 +1,93 @@
+"""Auth endpoint tests."""
+from __future__ import annotations
+
+from datetime import UTC, datetime, timedelta
+
+import jwt
+from flask import Flask
+from flask.testing import FlaskClient
+
+from backend.app.models import User
+
+
+def test_login_success(client: FlaskClient, admin_user: User) -> None:
+    resp = client.post(
+        "/api/auth/login", json={"username": "admin1", "password": "adminpass1"}
+    )
+    assert resp.status_code == 200
+    body = resp.get_json()
+    assert "access_token" in body and body["access_token"]
+    assert body["user"] == {"id": admin_user.id, "username": "admin1", "role": "admin"}
+
+
+def test_login_wrong_password(client: FlaskClient, admin_user: User) -> None:
+    resp = client.post(
+        "/api/auth/login", json={"username": "admin1", "password": "wrong"}
+    )
+    assert resp.status_code == 401
+    assert resp.get_json() == {"error": "Invalid credentials"}
+
+
+def test_login_unknown_user(client: FlaskClient) -> None:
+    resp = client.post(
+        "/api/auth/login", json={"username": "ghost", "password": "anything!!"}
+    )
+    assert resp.status_code == 401
+    # Generic message — must not leak whether username exists.
+    assert resp.get_json() == {"error": "Invalid credentials"}
+
+
+def test_login_missing_fields(client: FlaskClient) -> None:
+    resp = client.post("/api/auth/login", json={})
+    assert resp.status_code == 401
+
+
+def test_me_requires_token(client: FlaskClient) -> None:
+    resp = client.get("/api/auth/me")
+    assert resp.status_code == 401
+
+
+def test_me_returns_current_user(
+    client: FlaskClient, admin_user: User, admin_token: str
+) -> None:
+    resp = client.get("/api/auth/me", headers={"Authorization": f"Bearer {admin_token}"})
+    assert resp.status_code == 200
+    body = resp.get_json()
+    assert body["username"] == "admin1"
+    assert body["role"] == "admin"
+    assert "password_hash" not in body
+
+
+def test_me_with_invalid_token(client: FlaskClient) -> None:
+    resp = client.get("/api/auth/me", headers={"Authorization": "Bearer not.a.jwt"})
+    assert resp.status_code == 401
+
+
+def test_me_with_expired_token(
+    app: Flask, client: FlaskClient, admin_user: User
+) -> None:
+    now = datetime.now(UTC) - timedelta(minutes=120)
+    payload = {
+        "sub": str(admin_user.id),
+        "role": "admin",
+        "iat": int(now.timestamp()),
+        "exp": int((now + timedelta(minutes=1)).timestamp()),
+    }
+    token = jwt.encode(
+        payload, app.config["JWT_SECRET"], algorithm=app.config["JWT_ALGORITHM"]
+    )
+    resp = client.get("/api/auth/me", headers={"Authorization": f"Bearer {token}"})
+    assert resp.status_code == 401
+    assert resp.get_json() == {"error": "Token expired"}
+
+
+def test_logout_ok_with_token(client: FlaskClient, admin_token: str) -> None:
+    resp = client.post(
+        "/api/auth/logout", headers={"Authorization": f"Bearer {admin_token}"}
+    )
+    assert resp.status_code == 200
+
+
+def test_logout_without_token_is_401(client: FlaskClient) -> None:
+    resp = client.post("/api/auth/logout")
+    assert resp.status_code == 401