Add git to Dockerfile and httpx dependency

- Install git in Docker image for pip to clone git dependencies
- Add httpx package required by auth_service

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

requirements.txt

@@ -1,6 +1,7 @@
 fastapi>=0.109.0
 uvicorn>=0.27.0
 requests>=2.31.0
+httpx>=0.27.0
 cryptography>=42.0.0
 bcrypt>=4.0.0
 python-jose[cryptography]>=3.3.0