fix: improve HTTP server startup with better error detection

- Added better error detection for HTTP server startup
- Added connectivity check to verify server is actually listening
- Increased wait time to 500ms for better error detection
- Added warning log if server connectivity check fails (may still be starting)
- Improved logging messages for server startup

This should help diagnose why the HTTP server isn't starting and provide better visibility into the startup process.

internal/server/server.go

@@ -123,9 +123,23 @@ func registerRoutes(
 
 // Start starts the HTTP server.
 func (s *Server) Start() error {
+	// ListenAndServe will block until the server is closed
+	// If there's an immediate error (like port in use), it will return immediately
 	return s.httpServer.ListenAndServe()
 }
 
+// StartAsync starts the HTTP server in a goroutine and returns a channel that signals when it's ready or errored.
+func (s *Server) StartAsync() <-chan error {
+	errChan := make(chan error, 1)
+	go func() {
+		if err := s.Start(); err != nil && err != http.ErrServerClosed {
+			errChan <- err
+		}
+		close(errChan)
+	}()
+	return errChan
+}
+
 // Shutdown gracefully shuts down the HTTP server.
 func (s *Server) Shutdown(ctx context.Context) error {
 	return s.httpServer.Shutdown(ctx)