feat: init mirror-proxy project

- Docker Hub / GHCR / GitHub reverse proxy
- Web admin panel with link management
- Dynamic admin path, user and password config
- Rate limiting per link (dual/single auth mode)
- Docker and docker-compose deployment support
- GitHub Actions workflow for auto-publish to GHCR

.gitignore

@@ -0,0 +1,30 @@
+# Binaries
+mirror-proxy
+main
+*.exe
+
+# Build artifacts
+*.o
+*.a
+
+# Cache & runtime data
+cache/
+/cache
+*.log
+
+# Config (contains sensitive data, auto-generated at runtime)
+config.json
+
+# IDE
+.idea/
+.vscode/
+*.swp
+*.swo
+*~
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Go
+vendor/