feat(trigger): add system variables to webhook node outputs

Enhanced the TriggerWebhookNode to include system variables as outputs. This change allows for better accessibility of system variables during node execution, improving the overall functionality of the webhook trigger process. A TODO comment has been added to address future improvements for direct access to system variables.

api/core/workflow/nodes/trigger_webhook/node.py

@@ -1,6 +1,7 @@
 from collections.abc import Mapping
 from typing import Any, Optional
 
+from core.workflow.constants import SYSTEM_VARIABLE_NODE_ID
 from core.workflow.entities.workflow_node_execution import WorkflowNodeExecutionStatus
 from core.workflow.enums import ErrorStrategy, NodeExecutionType, NodeType
 from core.workflow.node_events import NodeRunResult
@@ -71,7 +72,12 @@ class TriggerWebhookNode(Node):
 
         # Extract webhook-specific outputs based on node configuration
         outputs = self._extract_configured_outputs(webhook_inputs)
+        system_inputs = self.graph_runtime_state.variable_pool.system_variables.to_dict()
 
+        # TODO: System variables should be directly accessible, no need for special handling
+        # Set system variables as node outputs.
+        for var in system_inputs:
+            outputs[SYSTEM_VARIABLE_NODE_ID + "." + var] = system_inputs[var]
         return NodeRunResult(
             status=WorkflowNodeExecutionStatus.SUCCEEDED,
             inputs=webhook_inputs,