Q56: disconnecting a provider stops the sessions using it

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/main/services/run-control.ts

@@ -17,12 +17,12 @@ export async function withRunControl<T>(runId: string, operation: () => Promise<
   }
 }
 
-/** Stops one in-flight run; false when it is not running in this process. */
-export function stopRun(runId: string): boolean {
+/** Stops one in-flight run with a reason; false when it is not running in this process. */
+export function stopRun(runId: string, reason: string = RUN_STOPPED_MESSAGE): boolean {
   const controller = controllers.get(runId);
   if (!controller) return false;
-  console.info(`[run-control] stopping run ${runId}`);
-  controller.abort();
+  console.info(`[run-control] stopping run ${runId}: ${reason}`);
+  controller.abort(new Error(reason));
   return true;
 }
 
@@ -37,17 +37,25 @@ export function currentRunSignal(): AbortSignal | undefined {
   return runSignals.getStore();
 }
 
+/** Why the current run was stopped, or null while it may continue. */
+export function runStopReason(): string | null {
+  const signal = currentRunSignal();
+  if (!signal?.aborted) return null;
+  return signal.reason instanceof Error ? signal.reason.message : RUN_STOPPED_MESSAGE;
+}
+
 export function throwIfRunStopped(): void {
-  if (currentRunSignal()?.aborted) throw new Error(RUN_STOPPED_MESSAGE);
+  const reason = runStopReason();
+  if (reason) throw new Error(reason);
 }
 
 /** Settles with the operation, or rejects as soon as the run is stopped; work without its own abort is abandoned. */
 export function untilStopped<T>(operation: Promise<T>): Promise<T> {
   const signal = currentRunSignal();
   if (!signal) return operation;
-  if (signal.aborted) return Promise.reject(new Error(RUN_STOPPED_MESSAGE));
+  if (signal.aborted) return Promise.reject(new Error(runStopReason() ?? RUN_STOPPED_MESSAGE));
   return new Promise<T>((resolve, reject) => {
-    const onAbort = () => reject(new Error(RUN_STOPPED_MESSAGE));
+    const onAbort = () => reject(new Error(runStopReason() ?? RUN_STOPPED_MESSAGE));
     signal.addEventListener("abort", onAbort, { once: true });
     operation.then(resolve, reject).finally(() => signal.removeEventListener("abort", onAbort));
   });