[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

requirements.txt

@@ -1,5 +1,8 @@
-fastapi
-uvicorn[standard]
+fastapi==0.135.2
+uvicorn[standard]==0.42.0
+PyJWT==2.12.1
+h11==0.16.0
+python-multipart>=1.3.1
 Cython==3.2.4
 opencv-python==4.10.0.84
 numpy==2.3.0
@@ -7,6 +10,5 @@ onnxruntime==1.22.0
 pynvml==12.0.0
 requests==2.32.4
 loguru==0.7.3
-python-multipart
 av==14.2.0
 xxhash==3.5.0