fix: 修复任务生命周期与调度就绪，优化执行和构建开销 (#3069)

* fix: harden task lifecycle and scheduler readiness

* fix: confine log writes to the configured log directory

* fix: verify complete build artifacts and untracked inputs

* fix: reconcile scheduler state and make stop win startup races

* fix: isolate cron generations and serialize scheduler recovery

back/api/system.ts

@@ -273,8 +273,11 @@ export default (app: Router) => {
             },
             onEnd: async (cp, endTime, diff) => {
               // Close the stream after task completion
-              await logStreamManager.closeStream(await handleLogPath(logPath));
-              res.end();
+              try {
+                await logStreamManager.closeStream(await handleLogPath(logPath));
+              } finally {
+                res.end();
+              }
             },
             onError: async (message: string) => {
               res.write(message);