feat: Enhance AI Knowledge sync process with full sync mode and attachment handling

steps/vmh/aiknowledge_full_sync_cron_step.py

@@ -69,11 +69,8 @@ async def handler(input_data: None, ctx: FlowContext[Any]) -> None:
                 'topic': 'aiknowledge.sync',
                 'data': {
                     'knowledge_id': entity['id'],
-                    'source': 'daily_full_sync'
-                }
-            })
-            
-            ctx.logger.info(
+                        'source': 'daily_full_sync',
+                        'full_sync': True  # Enable Blake3 verification
                 f"📤 [{i}/{total}] Enqueued: {entity['name']} "
                 f"(syncStatus={entity.get('syncStatus')})"
             )