Fix run recipe: optional fields in RunStatus, list->dict nodes

- Made recipe and inputs optional in RunStatus model
- Convert DAG nodes from list format to dict format when running recipes

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/routers/runs.py

@@ -41,8 +41,8 @@ class RunRequest(BaseModel):
 class RunStatus(BaseModel):
     run_id: str
     status: str
-    recipe: str
-    inputs: List[str]
+    recipe: Optional[str] = None
+    inputs: Optional[List[str]] = None
     output_name: Optional[str] = None
     created_at: Optional[str] = None
     completed_at: Optional[str] = None