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>

e2e/playwright.config.ts

@@ -0,0 +1,40 @@
+import { defineConfig, devices } from '@playwright/test';
+
+/**
+ * Single-container e2e setup — Mimic backend serves both /api/* and the built SPA.
+ *
+ * Sequence (run manually before `npx playwright test`):
+ *   1. make build && make start
+ *   2. make create-admin USER=root PASS=rootpass8
+ *   3. ensure `curl /api/health` is 200
+ *
+ * Tests run **serially** because all state lives in a single SQLite file in the
+ * shared container. RBAC tests need stable user fixtures across spec files.
+ */
+const baseURL = process.env.MIMIC_BASE_URL ?? 'http://localhost:5000';
+
+export default defineConfig({
+  testDir: './tests',
+  fullyParallel: false,
+  workers: 1,
+  retries: process.env.CI ? 1 : 0,
+  reporter: process.env.CI ? [['line'], ['html', { open: 'never' }]] : 'line',
+  timeout: 30_000,
+  expect: { timeout: 5_000 },
+  use: {
+    baseURL,
+    headless: true,
+    viewport: { width: 1280, height: 720 },
+    screenshot: 'only-on-failure',
+    trace: 'retain-on-failure',
+    actionTimeout: 10_000,
+    navigationTimeout: 15_000,
+    extraHTTPHeaders: { 'Content-Type': 'application/json' },
+  },
+  projects: [
+    {
+      name: 'chromium',
+      use: { ...devices['Desktop Chrome'] },
+    },
+  ],
+});