fix: make online updates recoverable

tests/update.test.ts

@@ -286,8 +286,27 @@ describe("更新安全工具", () => {
       expect(await readFile(path.join(config.currentLink, "dist", "marker"), "utf8")).toBe("new");
       const row = database.sqlite.prepare("SELECT operation, status FROM update_jobs WHERE id=?").get(jobId);
       expect(row).toEqual({ operation: "apply", status: "applying" });
-      finalizeUpdateJob(database.sqlite, jobId, "failed");
-      expect(database.sqlite.prepare("SELECT status FROM update_jobs WHERE id=?").get(jobId)).toEqual({ status: "failed" });
+      finalizeUpdateJob(database.sqlite, jobId, "failed", "健康检查失败（自定义）");
+      expect(database.sqlite.prepare("SELECT status, error_message AS errorMessage FROM update_jobs WHERE id=?").get(jobId)).toEqual({ status: "failed", errorMessage: "健康检查失败（自定义）" });
+      finalizeUpdateJob(database.sqlite, jobId, "failed", "第二次 finalize 不应覆盖原消息");
+      expect(database.sqlite.prepare("SELECT status, error_message AS errorMessage FROM update_jobs WHERE id=?").get(jobId)).toEqual({ status: "failed", errorMessage: "健康检查失败（自定义）" });
+      expect(database.sqlite.prepare("SELECT COUNT(*) AS count FROM audit_events WHERE action='update.failed' AND target_id=?").get(jobId)).toEqual({ count: 1 });
+      const defaultJobId = randomUUID();
+      database.sqlite.prepare(`
+        INSERT INTO update_jobs(id, operation, status, version, platform, asset_url, created_at, updated_at)
+        VALUES (?, 'apply', 'applying', '1.3.0', ?, ?, ?, ?)
+      `).run(defaultJobId, detectPlatform().target, "https://updates.example/" + assetName, now, now);
+      finalizeUpdateJob(database.sqlite, defaultJobId, "failed", "");
+      expect(database.sqlite.prepare("SELECT error_message AS errorMessage FROM update_jobs WHERE id=?").get(defaultJobId)).toEqual({ errorMessage: "新版本健康检查失败，已恢复上一版本" });
+      const completedJobId = randomUUID();
+      database.sqlite.prepare(`
+        INSERT INTO update_jobs(id, operation, status, version, platform, asset_url, created_at, updated_at)
+        VALUES (?, 'apply', 'completed', '1.3.0', ?, ?, ?, ?)
+      `).run(completedJobId, detectPlatform().target, "https://updates.example/" + assetName, now, now);
+      finalizeUpdateJob(database.sqlite, completedJobId, "completed");
+      expect(database.sqlite.prepare("SELECT COUNT(*) AS count FROM audit_events WHERE action='update.completed' AND target_id=?").get(completedJobId)).toEqual({ count: 0 });
+      expect(() => finalizeUpdateJob(database.sqlite, completedJobId, "failed", "不能降级已完成任务")).toThrow("更新任务状态不允许完成");
+      expect(database.sqlite.prepare("SELECT status FROM update_jobs WHERE id=?").get(completedJobId)).toEqual({ status: "completed" });
     } finally {
       globalThis.fetch = previousFetch;
       if (database) database.sqlite.close();
@@ -385,7 +404,7 @@ describe("更新安全工具", () => {
     }
   });
 
-  it("队列任务有新请求标记时可被重新检查，标记过期后才回收", async () => {
+  it("队列任务有匹配请求标记时保留到租约过期，过期后才回收", async () => {
     const root = await mkdtemp(path.join(tmpdir(), "tallynote-update-queued-marker-"));
     let database: ReturnType<typeof openDatabase> | undefined;
     try {
@@ -412,12 +431,14 @@ describe("更新安全工具", () => {
       const now = Date.now();
       await utimes(config.updateRequestPath, new Date(now), new Date(now));
 
-      expect(reconcileOrphanedUpdateJobs(database.sqlite, config, now)).toBe(1);
-      expect(database.sqlite.prepare("SELECT status FROM update_jobs WHERE id=?").get(jobId)).toEqual({ status: "failed" });
-      await expect(stat(config.updateRequestPath)).rejects.toThrow();
+      // The DB row is old, but the request marker is fresh and names this
+      // exact job. Keep it queued while systemd has a chance to consume it.
+      expect(reconcileOrphanedUpdateJobs(database.sqlite, config, now)).toBe(0);
+      expect(database.sqlite.prepare("SELECT status FROM update_jobs WHERE id=?").get(jobId)).toEqual({ status: "queued" });
+      await expect(stat(config.updateRequestPath)).resolves.toBeTruthy();
 
       const expiredNow = now + ORPHANED_UPDATE_TIMEOUT_MS + 1;
-      expect(reconcileOrphanedUpdateJobs(database.sqlite, config, expiredNow)).toBe(0);
+      expect(reconcileOrphanedUpdateJobs(database.sqlite, config, expiredNow)).toBe(1);
       expect(database.sqlite.prepare("SELECT status FROM update_jobs WHERE id=?").get(jobId)).toEqual({ status: "failed" });
       await expect(stat(config.updateRequestPath)).rejects.toThrow();
     } finally {