feat(server): implement structured logging, metrics, and dockerignore

- Configure structured logging via environment variable
- Add Prometheus metrics for HTTP request tracking and health
- Secure /metrics endpoint with IP allowlisting
- Update .dockerignore to exclude build artifacts

pyproject.toml

@@ -17,6 +17,7 @@ dependencies = [
     "requests>=2.32",
     "jinja2>=3.1",
     "wsproto>=1.2",
+    "prometheus-client>=0.20",
 ]
 
 [project.optional-dependencies]