fix(pi): converge worker failures and thinking state

tests/unit/pi-worker-pool-process-integration.test.ts

@@ -19,6 +19,7 @@ import {
 } from '../../electron/coding-runtime/pi/worker-pool';
 import {
   PiWorkerProcess,
+  type PiWorkerStopReason,
   type PiWorkerStopResult,
 } from '../../electron/coding-runtime/pi/worker-process';
 
@@ -60,8 +61,8 @@ class ProcessBackedWorker implements PiConversationWorker {
     return this.process.subscribeInvalidation(listener);
   }
 
-  stop(): Promise<PiWorkerStopResult> {
-    return this.process.stop();
+  stop(reason: PiWorkerStopReason): Promise<PiWorkerStopResult> {
+    return this.process.stop(reason);
   }
 }