Use source-specific polling settings in collection

- Read max_posts from source.max_posts (fallback to 100)
- Read fetch_comments from source settings
- Allows customizing collection per source

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

polling_service.py

@@ -161,14 +161,14 @@ class PollingService:
         end_iso = end_date.isoformat()
 
         try:
-            # Call the existing collect_platform function
+            # Call the existing collect_platform function using source settings
             posts_collected = collect_platform(
                 platform=source.platform,
                 community=source.source_id,
                 start_date=start_iso,
                 end_date=end_iso,
-                max_posts=100,  # Default limit
+                max_posts=source.max_posts or 100,
-                fetch_comments=True,
+                fetch_comments=source.fetch_comments if hasattr(source, 'fetch_comments') else True,
                 index=index,
                 dirs=dirs
             )