fix: address PR review comments

- Add error logging to CodexProvider auth check instead of silent failure
- Fix cachedAt timestamp to return actual cache time instead of request time
- Replace misleading hardcoded rate limit values (100) with sentinel value (-1)
- Fix unused parameter warning in codex routes

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

apps/server/src/services/codex-model-cache-service.ts

@@ -86,6 +86,24 @@ export class CodexModelCacheService {
     return this.refreshModels();
   }
 
+  /**
+   * Get models with cache metadata
+   *
+   * @param forceRefresh - If true, bypass cache and fetch fresh data
+   * @returns Object containing models and cache timestamp
+   */
+  async getModelsWithMetadata(
+    forceRefresh = false
+  ): Promise<{ models: CodexModel[]; cachedAt: number }> {
+    const models = await this.getModels(forceRefresh);
+
+    // Try to get the actual cache timestamp
+    const cached = await this.loadFromCache();
+    const cachedAt = cached?.cachedAt ?? Date.now();
+
+    return { models, cachedAt };
+  }
+
   /**
    * Refresh models from app-server and update cache
    *