feat(feedback): Add content improvement feedback system

Frontend (frontend/app.js):

- Add textarea for improvement feedback

- Add submit button with loading state

- Handle API response and display improved content

Backend (backend/copywriter.py):

- Add improve_copy() method using Cohere API

- Integrate retry mechanism for API calls

Backend (backend/main.py):

- Add /improve-content POST endpoint

- Implement error handling and return improved content with metadata

Testing:

- Verified feedback submission flow

- Confirmed improved content generation

- Tested error scenarios and loading states

backend/main.py

@@ -382,28 +382,36 @@ async def list_user_queries(
     page: int = Query(1, ge=1, description="Page number"),
     limit: int = Query(10, ge=1, le=100, description="Items per page")
 ):
-    """Retrieve a list of user queries."""
+    """List user queries with pagination."""
     try:
-        # Get all query files
-        query_files = glob.glob(str(Path(config.DATA_DIR) / "user_queries" / "*.json"))
-        query_files.sort(reverse=True)  # Sort by filename (timestamp) descending
+        # Calculate offset
+        offset = (page - 1) * limit
+        
+        # Get files from user_queries directory
+        query_dir = Path(config.DATA_DIR) / "user_queries"
+        query_dir.mkdir(exist_ok=True)
+        
+        # List all JSON files and sort by name (timestamp) in descending order
+        files = sorted(query_dir.glob("*.json"), reverse=True)
+        total = len(files)
         
         # Apply pagination
-        start_idx = (page - 1) * limit
-        end_idx = start_idx + limit
-        page_files = query_files[start_idx:end_idx]
+        files = files[offset:offset + limit]
         
         items = []
-        for file_path in page_files:
-            with open(file_path, 'r') as f:
+        for file in files:
+            with open(file, 'r') as f:
                 query_data = json.load(f)
                 items.append(query_data)
         
         return {
             "items": items,
-            "total": len(query_files),
-            "page": page,
-            "limit": limit
+            "pagination": {
+                "total": total,
+                "page": page,
+                "limit": limit,
+                "pages": (total + limit - 1) // limit
+            }
         }
     except Exception as e:
         logger.error(f"Error listing user queries: {str(e)}")