fix: Edge format normalization and nullable workflow_id

Fixes:
1. Edge Format Mismatch:
   - graph_data uses React Flow format (source/target)
   - WorkflowEdge expects backend format (from/to)
   - Added normalization in parse_workflow_graph()

2. UUID Validation Error:
   - workflow_id can be None when using graph_data (Phase 5)
   - save_execution_state now accepts Optional[str]
   - ExecutionResult uses "N/A" placeholder when None

Changes:
- workflow_engine.py: normalize edges before Pydantic validation
- workflow_executor.py: Optional[str] for workflow_id parameter

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

backend/workflow_engine.py

@@ -354,6 +354,9 @@ def parse_workflow_graph(graph_jsonb: Dict) -> WorkflowGraph:
 
     Args:
         graph_jsonb: JSONB dict aus workflow_definitions.graph
+                     Unterstützt beide Edge-Formate:
+                     - Backend: {"from": "...", "to": "..."}
+                     - Frontend: {"source": "...", "target": "..."}
 
     Returns:
         Validiertes WorkflowGraph-Objekt
@@ -361,6 +364,19 @@ def parse_workflow_graph(graph_jsonb: Dict) -> WorkflowGraph:
     Raises:
         ValidationError: Bei ungültigem Graph-Format
     """
+    # Normalize edges: convert React Flow format (source/target) to backend format (from/to)
+    if "edges" in graph_jsonb:
+        normalized_edges = []
+        for edge in graph_jsonb["edges"]:
+            normalized_edge = edge.copy()
+            # Convert source → from, target → to (if present)
+            if "source" in normalized_edge and "from" not in normalized_edge:
+                normalized_edge["from"] = normalized_edge.pop("source")
+            if "target" in normalized_edge and "to" not in normalized_edge:
+                normalized_edge["to"] = normalized_edge.pop("target")
+            normalized_edges.append(normalized_edge)
+        graph_jsonb = {**graph_jsonb, "edges": normalized_edges}
+
     return WorkflowGraph(**graph_jsonb)
 
 

backend/workflow_executor.py

@@ -201,7 +201,7 @@ async def execute_workflow(
         completed_at = datetime.utcnow().isoformat()
         save_execution_state(
             execution_id=execution_id,
-            workflow_id=workflow_id or "",  # Empty string if None (when graph_data is used)
+            workflow_id=workflow_id,  # Can be None when graph_data is used
             profile_id=profile_id,
             node_states=node_states if 'node_states' in locals() else [],
             status="failed",
@@ -212,7 +212,7 @@ async def execute_workflow(
 
         return ExecutionResult(
             execution_id=execution_id,
-            workflow_id=workflow_id or "",  # Empty string if None (when graph_data is used)
+            workflow_id=workflow_id or "N/A",  # ExecutionResult requires string, use placeholder
             status="failed",
             node_states=node_states if 'node_states' in locals() else [],
             aggregated_result={},
@@ -840,7 +840,7 @@ def aggregate_results(node_states: List[NodeExecutionState]) -> Dict[str, Any]:
 
 def save_execution_state(
     execution_id: str,
-    workflow_id: str,
+    workflow_id: Optional[str],  # None when using graph_data directly (Phase 5)
     profile_id: str,
     node_states: List[NodeExecutionState],
     status: str,
@@ -853,7 +853,7 @@ def save_execution_state(
 
     Args:
         execution_id: UUID der Execution
-        workflow_id: UUID des Workflows
+        workflow_id: UUID des Workflows (None wenn graph_data direkt verwendet wird)
         profile_id: UUID des Profils
         node_states: Liste aller NodeExecutionState
         status: 'completed' | 'failed' | 'partial'