feat: integrate Google Gemini with dynamic model fetching and UI support

- Added Gemini AI model integration with automatic model list fetching
- Updated configuration system to support Gemini API settings
- Enhanced SettingsDialog with Gemini model selection options
- Updated dependencies in package.json for Gemini support
- Improved provider configuration in index.ts for better model management
- Added Gemini API key field in sample configuration template
- Updated route configuration for Gemini support

ui/components/SettingsDialog.tsx

@@ -63,6 +63,7 @@ interface SettingsType {
   openaiApiKey: string;
   groqApiKey: string;
   anthropicApiKey: string;
+  geminiApiKey: string;
   ollamaApiUrl: string;
 }
 
@@ -476,6 +477,22 @@ const SettingsDialog = ({
                         }
                       />
                     </div>
+                    <div className="flex flex-col space-y-1">
+                      <p className="text-black/70 dark:text-white/70 text-sm">
+                        Gemini API Key
+                      </p>
+                      <Input
+                        type="text"
+                        placeholder="Gemini API key"
+                        defaultValue={config.geminiApiKey}
+                        onChange={(e) =>
+                          setConfig({
+                            ...config,
+                            geminiApiKey: e.target.value,
+                          })
+                        }
+                      />
+                    </div>
                   </div>
                 )}
                 {isLoading && (