fix: synchronize runtime locales and harden online updates

Translate UI, scheduler, validation, preload and maintenance messages dynamically, and propagate locale changes between workers. Harden update checks, downloads and terminal states, verify Debian pnpm, and ignore generated test artifacts.

test/back/shell-upgrade.test.cjs

@@ -225,6 +225,7 @@ for (const branch of ['master', 'develop', 'debian', 'debian-dev'])
     const f = await fixture(t, { branch, lockChange: true, tee: true });
     let result = await f.execute('update', 'false');
     assert.equal(result.code, 0, result.stdout + result.stderr);
+    assert.ok(result.stdout.includes('　　　　　'), 'update logs retain the completion marker');
     assert.equal(f.read('version.yaml'), 'version: 2.21.0');
     assert.equal(fs.existsSync(path.join(f.root, 'stops')), false);
     assert.match(
@@ -295,7 +296,7 @@ test('failed health checks and concurrent upgrades are rejected', async (t) => {
   await withUpgradeLock(tmp, async () => {
     await assert.rejects(
       withUpgradeLock(tmp, async () => {}),
-      /Another upgrade/,
+      /Another upgrade|已有更新或重载/,
     );
   });
   assert.deepEqual(fs.readdirSync(tmp), []);
@@ -307,6 +308,6 @@ test('failed health checks and concurrent upgrades are rejected', async (t) => {
   t.after(() => new Promise((resolve) => server.close(resolve)));
   await assert.rejects(
     waitForHealth({ QlPort: String(server.address().port) }, 20),
-    /health check/,
+    /health check|后端启动检查失败/,
   );
 });