feat: add webhook node limit validation (max 5 per workflow)

- Add MAX_WEBHOOK_NODES_PER_WORKFLOW constant set to 5
- Validate webhook node count in sync_webhook_relationships method
- Raise ValueError when workflow exceeds webhook node limit
- Block workflow save when limit is exceeded to ensure data integrity
- Provide clear error message indicating current count and maximum allowed

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

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

api/controllers/console/app/workflow_trigger.py

@@ -167,7 +167,7 @@ class AppTriggersApi(Resource):
         """Get app triggers list"""
         assert isinstance(current_user, Account)
         assert current_user.current_tenant_id is not None
-        
+
         with Session(db.engine) as session:
             # Get all triggers for this app using select API
             triggers = (

api/events/event_handlers/sync_webhook_when_app_created.py

@@ -1,8 +1,12 @@
+import logging
+
 from events.app_event import app_draft_workflow_was_synced
 from models.model import App, AppMode
 from models.workflow import Workflow
 from services.webhook_service import WebhookService
 
+logger = logging.getLogger(__name__)
+
 
 @app_draft_workflow_was_synced.connect
 def handle(sender, synced_draft_workflow: Workflow, **kwargs):
@@ -15,5 +19,4 @@ def handle(sender, synced_draft_workflow: Workflow, **kwargs):
         # only handle workflow app, chatflow is not supported yet
         return
 
-    # sync webhook relationships in DB
     WebhookService.sync_webhook_relationships(app, synced_draft_workflow)

api/services/webhook_service.py

@@ -33,6 +33,7 @@ class WebhookService:
     """Service for handling webhook operations."""
 
     __WEBHOOK_NODE_CACHE_KEY__ = "webhook_nodes"
+    MAX_WEBHOOK_NODES_PER_WORKFLOW = 5  # Maximum allowed webhook nodes per workflow
 
     @classmethod
     def get_webhook_trigger_and_workflow(
@@ -611,6 +612,9 @@ class WebhookService:
         Approach:
         Frequent DB operations may cause performance issues, using Redis to cache it instead.
         If any record exists, cache it.
+
+        Limits:
+        - Maximum 5 webhook nodes per workflow
         """
 
         class Cache(BaseModel):
@@ -624,6 +628,13 @@ class WebhookService:
 
         nodes_id_in_graph = [node_id for node_id, _ in workflow.walk_nodes(NodeType.TRIGGER_WEBHOOK)]
 
+        # Check webhook node limit
+        if len(nodes_id_in_graph) > cls.MAX_WEBHOOK_NODES_PER_WORKFLOW:
+            raise ValueError(
+                f"Workflow exceeds maximum webhook node limit. "
+                f"Found {len(nodes_id_in_graph)} webhook nodes, maximum allowed is {cls.MAX_WEBHOOK_NODES_PER_WORKFLOW}"
+            )
+
         not_found_in_cache: list[str] = []
         for node_id in nodes_id_in_graph:
             # firstly check if the node exists in cache