Fix recipe run endpoint to accept JSON body

Use Pydantic model for inputs parameter.

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

app/routers/recipes.py

@@ -28,6 +28,10 @@ class RecipeUploadRequest(BaseModel):
     description: Optional[str] = None
 
 
+class RecipeRunRequest(BaseModel):
+    inputs: List[str] = []
+
+
 def get_recipe_service():
     """Get recipe service instance."""
     return RecipeService(get_redis_client(), get_cache_manager())
@@ -155,7 +159,7 @@ async def delete_recipe(
 @router.post("/{recipe_id}/run")
 async def run_recipe(
     recipe_id: str,
-    inputs: List[str],
+    req: RecipeRunRequest,
     ctx: UserContext = Depends(require_auth),
     recipe_service: RecipeService = Depends(get_recipe_service),
 ):
@@ -172,7 +176,7 @@ async def run_recipe(
     run_service = RunService(database, get_redis_client(), get_cache_manager())
     run, error = await run_service.create_run(
         recipe=recipe.get("name", recipe_id),
-        inputs=inputs,
+        inputs=req.inputs,
         use_dag=True,
         actor_id=ctx.actor_id,
         l2_server=ctx.l2_server,