feat(delegate-task): ⚙️ make sync subagent timeout configurable via syncPollTimeoutMs

Allow users to set `background_task.syncPollTimeoutMs` in config to override
the default 10-minute sync subagent timeout. Affects sync task, sync continuation,
and unstable agent task paths. Minimum value: 60000ms (1 minute).

Co-authored-by: Wine Fox <fox@ling.plus>

src/tools/delegate-task/sync-task.ts

@@ -23,7 +23,7 @@ export async function executeSyncTask(
   fallbackChain?: import("../../shared/model-requirements").FallbackEntry[],
   deps: SyncTaskDeps = syncTaskDeps
 ): Promise<string> {
-  const { client, directory, onSyncSessionCreated } = executorCtx
+  const { client, directory, onSyncSessionCreated, syncPollTimeoutMs } = executorCtx
   const toastManager = getTaskToastManager()
   let taskId: string | undefined
   let syncSessionID: string | undefined
@@ -117,7 +117,7 @@ export async function executeSyncTask(
         agentToUse,
         toastManager,
         taskId,
-      })
+      }, syncPollTimeoutMs)
       if (pollError) {
         return pollError
       }