feat(auth): Implement GitHub OAuth authentication flow for package publishing

- Added authentication service and GitHub OAuth integration.
- Introduced new authentication methods and structures in the model.
- Updated the API to handle authentication during the publishing process.
- Created handlers for starting and checking the status of the OAuth flow.
- Enhanced the publish handler to validate authentication credentials.
- Updated configuration to include GitHub OAuth settings.
- Added tests for the OAuth flow and publishing with authentication.
- Updated documentation to reflect changes in the API and authentication process.

internal/api/router/v0.go

@@ -5,18 +5,19 @@ import (
 	"net/http"
 
 	v0 "github.com/modelcontextprotocol/registry/internal/api/handlers/v0"
+	"github.com/modelcontextprotocol/registry/internal/auth"
 	"github.com/modelcontextprotocol/registry/internal/config"
 	"github.com/modelcontextprotocol/registry/internal/service"
 )
 
 // RegisterV0Routes registers all v0 API routes to the provided router
-func RegisterV0Routes(mux *http.ServeMux, cfg *config.Config, registry service.RegistryService) {
+func RegisterV0Routes(mux *http.ServeMux, cfg *config.Config, registry service.RegistryService, authService auth.Service) {
 	// Register v0 endpoints
 	mux.HandleFunc("/v0/health", v0.HealthHandler())
 	mux.HandleFunc("/v0/servers", v0.ServersHandler(registry))
 	mux.HandleFunc("/v0/servers/{id}", v0.ServersDetailHandler(registry))
 	mux.HandleFunc("/v0/ping", v0.PingHandler(cfg))
-	mux.HandleFunc("/v0/publish", v0.PublishHandler(registry))
+	mux.HandleFunc("/v0/publish", v0.PublishHandler(registry, authService))
 
 	// Register Swagger UI routes
 	mux.HandleFunc("/v0/swagger/", v0.SwaggerHandler())