feat(GeminiAgent): expand available Gemini models and update RPM limits

- Added new Gemini model types: 'gemini-2.5-pro', 'gemini-2.0-flash', and 'gemini-2.0-flash-lite'.
- Updated RPM limits for existing and new models.
- Enhanced model selection logic to validate configured model against available options, with fallback to a default model.

src/services/worker/GeminiAgent.ts

@@ -25,14 +25,21 @@ import { ModeManager } from '../domain/ModeManager.js';
 // Gemini API endpoint
 const GEMINI_API_URL = 'https://generativelanguage.googleapis.com/v1beta/models';
 
-// Gemini model types (free tier models)
-export type GeminiModel = 'gemini-2.5-flash-lite' | 'gemini-2.5-flash' | 'gemini-3-flash';
+// Gemini model types (available via API)
+export type GeminiModel =
+  | 'gemini-2.5-flash-lite'
+  | 'gemini-2.5-flash'
+  | 'gemini-2.5-pro'
+  | 'gemini-2.0-flash'
+  | 'gemini-2.0-flash-lite';
 
 // Free tier RPM limits by model (requests per minute)
 const GEMINI_RPM_LIMITS: Record<GeminiModel, number> = {
   'gemini-2.5-flash-lite': 10,
-  'gemini-2.5-flash': 5,
-  'gemini-3-flash': 5,
+  'gemini-2.5-flash': 10,
+  'gemini-2.5-pro': 5,
+  'gemini-2.0-flash': 15,
+  'gemini-2.0-flash-lite': 30,
 };
 
 // Track last request time for rate limiting
@@ -246,8 +253,6 @@ export class GeminiAgent {
         historyLength: session.conversationHistory.length
       });
 
-      this.dbManager.getSessionStore().markSessionCompleted(session.sessionDbId);
-
     } catch (error: any) {
       if (error.name === 'AbortError') {
         logger.warn('SDK', 'Gemini agent aborted', { sessionId: session.sessionDbId });
@@ -518,8 +523,27 @@ export class GeminiAgent {
     // API key: check settings first, then environment variable
     const apiKey = settings.CLAUDE_MEM_GEMINI_API_KEY || process.env.GEMINI_API_KEY || '';
 
-    // Model: from settings or default (gemini-2.5-flash-lite has highest free tier RPM)
-    const model = (settings.CLAUDE_MEM_GEMINI_MODEL || 'gemini-2.5-flash-lite') as GeminiModel;
+    // Model: from settings or default, with validation
+    const defaultModel: GeminiModel = 'gemini-2.5-flash';
+    const configuredModel = settings.CLAUDE_MEM_GEMINI_MODEL || defaultModel;
+    const validModels: GeminiModel[] = [
+      'gemini-2.5-flash-lite',
+      'gemini-2.5-flash',
+      'gemini-2.5-pro',
+      'gemini-2.0-flash',
+      'gemini-2.0-flash-lite',
+    ];
+
+    let model: GeminiModel;
+    if (validModels.includes(configuredModel as GeminiModel)) {
+      model = configuredModel as GeminiModel;
+    } else {
+      logger.warn('SDK', `Invalid Gemini model "${configuredModel}", falling back to ${defaultModel}`, {
+        configured: configuredModel,
+        validModels,
+      });
+      model = defaultModel;
+    }
 
     // Billing: if enabled, skip rate limiting (1000+ RPM available)
     const billingEnabled = settings.CLAUDE_MEM_GEMINI_BILLING_ENABLED === 'true';