Add melange/apko build pipeline and Kubernetes manifests

- Add melange.yaml for distroless package build
- Add apko.yaml for minimal container image
- Add GitHub Actions workflow for melange/apko CI build
- Add Kubernetes manifests (deployment, service, configmap, secret, redis)
- Update Dockerfile, .gitignore, and docker-compose.yml

requirements.prod.txt

@@ -0,0 +1,15 @@
+fastapi==0.115.0
+uvicorn[standard]==0.30.6
+pyyaml==6.0.2
+redis==5.0.7
+pydantic==2.9.2
+pydantic-settings==2.5.2
+jinja2==3.1.4
+python-multipart==0.0.9
+orjson==3.10.7
+passlib[argon2]==1.7.4
+itsdangerous==2.2.0
+slowapi==0.1.9
+python-json-logger==2.0.7
+tenacity==9.0.0
+prometheus-client==0.21.0