Align usage dashboard with CCSwitch

Filter request logs to model API calls and add request, provider, model, and settings tabs.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

internal/gateway/messages.go

@@ -34,6 +34,7 @@ func (s *Server) handleMessages(w http.ResponseWriter, r *http.Request) {
 
 	rec := recordFrom(r)
 	rec.update(func(e *LogEntry) {
+		e.Provider = provider.Name
 		e.Model = model
 		e.InputTokens = anthropic.EstimateTokens(&req)
 	})