[AZ-178] Fix Critical/High security findings: auth, CVEs, non-root containers, per-job SSE

- Pin all deps; h11==0.16.0 (CVE-2025-43859), python-multipart>=1.3.1 (CVE-2026-28356), PyJWT==2.12.1
- Add HMAC JWT verification (require_auth FastAPI dependency, JWT_SECRET-gated)
- Fix TokenManager._refresh() to use ADMIN_API_URL instead of ANNOTATIONS_URL
- Rename POST /detect → POST /detect/image (image-only, rejects video files)
- Replace global SSE stream with per-job SSE: GET /detect/{media_id} with event replay buffer
- Apply require_auth to all 4 protected endpoints
- Fix on_annotation/on_status closure to use mutable current_id for correct post-upload event routing
- Add non-root appuser to Dockerfile and Dockerfile.gpu
- Add JWT_SECRET to e2e/docker-compose.test.yml and run-tests.sh
- Update all e2e tests and unit tests for new endpoints and HMAC token signing
- 64/64 tests pass

Made-with: Cursor

e2e/tests/test_async_sse.py

@@ -41,7 +41,7 @@ def test_ft_p09_sse_event_delivery(
 
     def _listen():
         try:
-            with sse_client_factory() as sse:
+            with sse_client_factory(media_id) as sse:
                 time.sleep(0.3)
                 for event in sse.events():
                     if not event.data or not str(event.data).strip():