fix: remove folder icons, add single run for maintenance, fix batch 400

- Remove AddToFolderMenu from grid/list/table library views (folders removed)
- Add single "Run" button to MaintenanceFlowDetailPage alongside Batch Launch
- Change seed script to publish maintenance flows (batch rejects drafts)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/scripts/seed_maintenance_flows.py

@@ -766,7 +766,7 @@ async def create_maintenance_flow(client: httpx.AsyncClient, token: str, flow_da
 
     flow_data["is_default"] = True
     flow_data["is_public"] = True
-    flow_data["status"] = "draft"
+    flow_data["status"] = "published"
 
     # Check if flow with same name exists
     list_response = await client.get(f"{API_BASE_URL}/trees", headers=headers, params={"tree_type": "maintenance"})