fix: Phase 5 - Workflow save + node persistence bugs

KRITISCHE FIXES:

1. Backend: Workflow-Type Support
   - models.py: graph_data Feld hinzugefügt
   - models.py: slug Optional (auto-generiert)
   - prompts.py: 'workflow' in erlaubten Typen
   - prompts.py: graph_data in INSERT/UPDATE
   - prompts.py: Auto-Slug-Generierung aus Name
   - FIX: "Field required: slug" Error behoben

2. Frontend: Node-Updates Persistence
   - selectedNode sync mit nodes array (useEffect)
   - FIX: Änderungen gingen verloren (stale state)
   - FIX: Prompt-Auswahl nicht sichtbar nach Edit
   - FIX: Fallback-Strategy nicht gespeichert
   - FIX: Node-Name Änderungen nicht übernommen

BEHOBEN:
- ❌ Save fehlgeschlagen → ✅ Workflows speicherbar
- ❌ Node-Name ignoriert → ✅ Live-Update
- ❌ Prompt verschwindet → ✅ Bleibt sichtbar
- ❌ Fallback nicht saved → ✅ Persistiert

Tested: Backend API akzeptiert jetzt type='workflow'

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

backend/models.py

@@ -177,12 +177,12 @@ class StageCreate(BaseModel):
 
 
 class UnifiedPromptCreate(BaseModel):
-    """Create a new unified prompt (base or pipeline type)"""
+    """Create a new unified prompt (base, pipeline, or workflow type)"""
     name: str
-    slug: str
+    slug: Optional[str] = None  # Auto-generated from name if not provided
     display_name: Optional[str] = None
     description: Optional[str] = None
-    type: str  # 'base' or 'pipeline'
+    type: str  # 'base' | 'pipeline' | 'workflow'
     category: str = 'ganzheitlich'
     active: bool = True
     sort_order: int = 0
@@ -195,6 +195,9 @@ class UnifiedPromptCreate(BaseModel):
     # For pipeline prompts (multi-stage workflow)
     stages: Optional[list[StageCreate]] = None  # Required if type='pipeline'
 
+    # For workflow prompts (visual graph editor)
+    graph_data: Optional[dict] = None  # Required if type='workflow'
+
 
 class UnifiedPromptUpdate(BaseModel):
     """Update an existing unified prompt"""
@@ -209,6 +212,7 @@ class UnifiedPromptUpdate(BaseModel):
     output_format: Optional[str] = None
     output_schema: Optional[dict] = None
     stages: Optional[list[StageCreate]] = None
+    graph_data: Optional[dict] = None  # For workflow type
 
 
 # ── Pipeline Config Models (Issue #28) ─────────────────────────────────────

backend/routers/prompts.py

@@ -1380,20 +1380,26 @@ async def execute_unified_prompt(
 @router.post("/unified")
 def create_unified_prompt(p: UnifiedPromptCreate, session: dict = Depends(require_admin)):
     """
-    Create a new unified prompt (base or pipeline type).
+    Create a new unified prompt (base, pipeline, or workflow type).
     Admin only.
     """
     with get_db() as conn:
         cur = get_cursor(conn)
 
+        # Auto-generate slug if not provided (for workflows)
+        if not p.slug:
+            import re
+            base_slug = re.sub(r'[^a-z0-9_]+', '_', p.name.lower()).strip('_')
+            p.slug = f"{base_slug}_{uuid.uuid4().hex[:6]}"
+
         # Check for duplicate slug
         cur.execute("SELECT id FROM ai_prompts WHERE slug=%s", (p.slug,))
         if cur.fetchone():
             raise HTTPException(status_code=400, detail="Slug already exists")
 
         # Validate type
-        if p.type not in ['base', 'pipeline']:
+        if p.type not in ['base', 'pipeline', 'workflow']:
-            raise HTTPException(status_code=400, detail="Type must be 'base' or 'pipeline'")
+            raise HTTPException(status_code=400, detail="Type must be 'base', 'pipeline', or 'workflow'")
 
         # Validate base type has template
         if p.type == 'base' and not p.template:
@@ -1403,6 +1409,10 @@ def create_unified_prompt(p: UnifiedPromptCreate, session: dict = Depends(requir
         if p.type == 'pipeline' and not p.stages:
             raise HTTPException(status_code=400, detail="Pipeline prompts require stages")
 
+        # Validate workflow type has graph_data
+        if p.type == 'workflow' and not p.graph_data:
+            raise HTTPException(status_code=400, detail="Workflow prompts require graph_data")
+
         # Convert stages to JSONB
         stages_json = None
         if p.stages:
@@ -1426,16 +1436,22 @@ def create_unified_prompt(p: UnifiedPromptCreate, session: dict = Depends(requir
 
         prompt_id = str(uuid.uuid4())
 
+        # Convert graph_data to JSONB
+        graph_data_json = None
+        if p.graph_data:
+            graph_data_json = json.dumps(p.graph_data)
+
         cur.execute(
             """INSERT INTO ai_prompts
                (id, slug, name, display_name, description, template, category, active, sort_order,
-                type, stages, output_format, output_schema)
+                type, stages, output_format, output_schema, graph_data)
-               VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)""",
+               VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)""",
             (
                 prompt_id, p.slug, p.name, p.display_name, p.description,
                 p.template, p.category, p.active, p.sort_order,
                 p.type, stages_json, p.output_format,
-                json.dumps(p.output_schema) if p.output_schema else None
+                json.dumps(p.output_schema) if p.output_schema else None,
+                graph_data_json
             )
         )
 
@@ -1470,8 +1486,8 @@ def update_unified_prompt(prompt_id: str, p: UnifiedPromptUpdate, session: dict
             updates.append('description=%s')
             values.append(p.description)
         if p.type is not None:
-            if p.type not in ['base', 'pipeline']:
+            if p.type not in ['base', 'pipeline', 'workflow']:
-                raise HTTPException(status_code=400, detail="Type must be 'base' or 'pipeline'")
+                raise HTTPException(status_code=400, detail="Type must be 'base', 'pipeline', or 'workflow'")
             updates.append('type=%s')
             values.append(p.type)
         if p.category is not None:
@@ -1512,6 +1528,9 @@ def update_unified_prompt(prompt_id: str, p: UnifiedPromptUpdate, session: dict
             ])
             updates.append('stages=%s')
             values.append(stages_json)
+        if p.graph_data is not None:
+            updates.append('graph_data=%s')
+            values.append(json.dumps(p.graph_data))
 
         if not updates:
             return {"ok": True}

frontend/src/pages/WorkflowEditorPage.jsx

@@ -73,6 +73,16 @@ export default function WorkflowEditorPage() {
     setValidationWarnings(warnings)
   }, [nodes, edges])
 
+  // Keep selectedNode in sync with nodes array (wichtig für Config Panel!)
+  useEffect(() => {
+    if (selectedNode) {
+      const updatedNode = nodes.find(n => n.id === selectedNode.id)
+      if (updatedNode && updatedNode !== selectedNode) {
+        setSelectedNode(updatedNode)
+      }
+    }
+  }, [nodes])
+
   // ── Handlers ──────────────────────────────────────────────────────────────
 
   const onConnect = useCallback(