fix: address review feedback on duplicate instance prevention

- Add stale-instance guard in self-start setTimeout: skip if this
  instance was already replaced by a newer register() call.
- ViewerServer.stop(): add 3s timeout fallback and Node 18.0.x compat
  (closeIdleConnections + unref when closeAllConnections is missing).
- Use explicit error formatting in cleanup catch block.
- Bind error handler before listen() in test helper.

Author: fancyboi999

apps/memos-local-openclaw/index.ts

@@ -2424,7 +2424,7 @@ Groups: ${groupNames.length > 0 ? groupNames.join(", ") : "(none)"}`,
           await instanceToReplace.telemetry.shutdown().catch(() => {});
           instanceToReplace.store.close();
         } catch (err) {
-          api.logger.warn(`memos-local: previous instance cleanup error: ${err}`);
+          api.logger.warn(`memos-local: previous instance cleanup error: ${err instanceof Error ? err.message : String(err)}`);
         }
         api.logger.info("memos-local: previous instance stopped");
       }
@@ -2489,6 +2489,8 @@ Groups: ${groupNames.length > 0 ? groupNames.join(", ") : "(none)"}`,
     // service.start() immediately after registration.
     const SELF_START_DELAY_MS = 0;
     setTimeout(() => {
+      // Abort if this instance was already replaced by a newer register() call
+      if (activeInstances.get(stateDir)?.viewer !== viewer) return;
       if (!serviceStarted) {
         api.logger.info("memos-local: service.start() not called by host, self-starting viewer...");
         startServiceCore().catch((err) => {

apps/memos-local-openclaw/src/viewer/server.ts

@@ -220,9 +220,20 @@ export class ViewerServer {
     const srv = this.server;
     this.server = null;
     return new Promise<void>((resolve) => {
-      srv.close(() => resolve());
-      // Force-close idle keep-alive connections so close() doesn't hang
-      srv.closeAllConnections?.();
+      const timeout = setTimeout(() => resolve(), 3000);
+      srv.close(() => { clearTimeout(timeout); resolve(); });
+      // Force-close idle keep-alive sockets. closeAllConnections is
+      // available from Node 18.2; fall back to destroying tracked sockets.
+      if (typeof srv.closeAllConnections === "function") {
+        srv.closeAllConnections();
+      } else {
+        // Older Node: close idle connections via closeIdleConnections
+        // (18.0+) or just unref so the event loop can exit.
+        if (typeof (srv as any).closeIdleConnections === "function") {
+          (srv as any).closeIdleConnections();
+        }
+        srv.unref();
+      }
     });
   }
 

apps/memos-local-openclaw/tests/e2e-duplicate-instance.test.ts

@@ -24,11 +24,11 @@ fs.mkdirSync(path.join(tmpDir, "skills"), { recursive: true });
 function findFreePort(): Promise<number> {
   return new Promise((resolve, reject) => {
     const srv = net.createServer();
+    srv.on("error", reject);
     srv.listen(0, "127.0.0.1", () => {
       const port = (srv.address() as net.AddressInfo).port;
       srv.close(() => resolve(port));
     });
-    srv.on("error", reject);
   });
 }