Add initial implementation of gitea-mcp-forward-auth microservice

- Create build and release workflows for CI/CD
- Implement Dockerfile for multi-stage builds
- Add core authentication logic with token validation
- Include HTTP handler for authorization checks
- Set up Kubernetes deployment and service manifests
- Update README with usage instructions and configuration details

.gitignore

@@ -8,6 +8,7 @@
 *.dll
 *.so
 *.dylib
+authproxy
 
 # Test binary, built with `go test -c`
 *.test