refactor(adk): use generated tasks.interrupt now that it's in the SDK (AGX1-391)

scale-agentex#365 merged and Stainless regenerated client.tasks.interrupt, so drop the interim generic POST in the adk interrupt service and call the typed method (matches cancel_task).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: declan-scale

src/agentex/lib/core/services/adk/tasks.py

@@ -112,14 +112,7 @@ async def interrupt_task(
             input={"task_id": task_id, "reason": reason},
         ) as span:
             heartbeat_if_in_workflow("interrupt task")
-            # TODO(AGX1-391): switch to self._agentex_client.tasks.interrupt(...) once the
-            # POST /tasks/{id}/interrupt endpoint is added to the Stainless config and
-            # regenerated. Using the generic post keeps this working before regeneration.
-            task_model = await self._agentex_client.post(
-                f"/tasks/{task_id}/interrupt",
-                cast_to=Task,
-                body={"reason": reason},
-            )
+            task_model = await self._agentex_client.tasks.interrupt(task_id=task_id, reason=reason)
             if span:
                 span.output = task_model.model_dump()
             return task_model

src/agentex/protocol/acp.py

@@ -138,12 +138,3 @@ class InterruptTaskParams(BaseModel):
     RPCMethod.TASK_CREATE: CreateTaskParams,
     RPCMethod.TASK_INTERRUPT: InterruptTaskParams,
 }
-
-# TODO(interrupt): the client-facing REST method ``client.tasks.interrupt(task_id,
-# reason=...)`` plus its param/response types (``task_interrupt_params.py``) and the
-# ``AgentRPCMethod`` union additions are Stainless-GENERATED. They regenerate from the
-# upstream OpenAPI change in scale-agentex (design doc sections 9.1 / 9.2) once
-# ``TASK_INTERRUPT`` and the ``POST /tasks/{task_id}/interrupt`` route land there. Do NOT
-# hand-write them under ``src/agentex/resources/**`` or ``src/agentex/types/**``. The
-# hand-editable protocol shapes above (and the agent-side hook in ``agentex.lib.**``)
-# survive regeneration and are what agents rely on today.