feat(providers): add Ollama provider support

- Implement OllamaProvider with OpenAI-compatible API integration
- Add Ollama to provider initialization in server.go
- Update config.go to handle Ollama (no API key required)
- Configure .env with Ollama server at 172.20.1.222:11434
- Support models: glm-4.7-flash:latest, qwen3-coder:30b, gemma4:26b

internal/server/server.go

@@ -75,7 +75,7 @@ func (s *Server) RefreshProviders() error {
 		dbMap[cfg.ID] = cfg
 	}
 
-	providerIDs := []string{"openai", "gemini", "deepseek", "moonshot", "grok"}
+	providerIDs := []string{"openai", "gemini", "deepseek", "moonshot", "grok", "ollama"}
 	for _, id := range providerIDs {
 		// Default values from config
 		enabled := false
@@ -152,6 +152,10 @@ func (s *Server) RefreshProviders() error {
 			cfg := s.cfg.Providers.Grok
 			cfg.BaseURL = baseURL
 			s.providers["grok"] = providers.NewGrokProvider(cfg, apiKey)
+		case "ollama":
+			cfg := s.cfg.Providers.Ollama
+			cfg.BaseURL = baseURL
+			s.providers["ollama"] = providers.NewOllamaProvider(cfg)
 		}
 	}