feat(api): Add app_id field to HumanInputForm model

This ensures that `HumanInputForm` could be associated to a specific
application without relying on `WorkflowRun`, providing us a smoother
migration path if we want to implement test form.

api/services/human_input_service.py

@@ -42,6 +42,14 @@ class Form:
     def workflow_run_id(self) -> str:
         return self._record.workflow_run_id
 
+    @property
+    def tenant_id(self) -> str:
+        return self._record.tenant_id
+
+    @property
+    def app_id(self) -> str:
+        return self._record.app_id
+
     @property
     def recipient_id(self) -> str | None:
         return self._record.recipient_id