feat(cli): add CLI application with automatic command generation from swagger

Add a new CLI application (`cmd/cli/`) that generates command-line interface commands from the API swagger specification. Includes:
- Main CLI entry point with command parsing and execution
- Code generator that reads swagger.json and generates typed command handlers
- Makefile targets (`gen-cli`, `build-cli`) for generating and building the CLI
- GitHub Actions workflow to build cross-platform CLI binaries (linux/amd64, linux/arm64)

cmd/cli/go.mod

@@ -0,0 +1,10 @@
+module github.com/yusing/godoxy/cli
+
+go 1.26.0
+
+require (
+	github.com/gorilla/websocket v1.5.3
+	github.com/yusing/goutils v0.7.0
+)
+
+replace github.com/yusing/goutils => ../../goutils