feat: 加固运行期可靠性并补齐调度与观测接口

- 运行句柄按 run_id 归属，修复取消后重跑时闸门被旧运行删除的竞态
- 调度循环改用取消令牌退出，启动时对账遗留运行，校验 rows_affected
- 三类任务统一参与调度，新增 /api/v1/stats 与 /api/v1/schedule
- SQLite 启用 WAL 与 busy_timeout，日志清理跳过活跃文件，单行上限 256 KiB
- 前端缓存管理令牌并在 403 时重试一次，仪表盘改用统计接口

frontend/src/App.test.tsx

@@ -68,6 +68,21 @@ function createFetchMock(options: FetchMockOptions = {}) {
       if (url.endsWith('/api/v1/session')) {
         return jsonResponse({ token: 'test-token' })
       }
+      if (url.endsWith('/api/v1/stats')) {
+        return jsonResponse({
+          total: 1,
+          enabled: 1,
+          running: 0,
+          script: 1,
+          http: 0,
+          process: 0,
+        })
+      }
+      if (url.endsWith('/api/v1/schedule')) {
+        return jsonResponse([
+          { task_id: 'echo_task', next_run_at: '2026-10-19T02:00:00Z' },
+        ])
+      }
       if (url.endsWith('/api/v1/cron/preview')) {
         return jsonResponse({
           timezone: 'Asia/Shanghai',
@@ -152,6 +167,13 @@ describe('TaskDashboard', () => {
     expect(await screen.findByText('在线')).toBeInTheDocument()
   })
 
+  it('shows the next run time reported by the schedule endpoint', async () => {
+    vi.stubGlobal('fetch', createFetchMock())
+    renderApp()
+
+    expect(await screen.findByText(/下次/)).toBeInTheDocument()
+  })
+
   it('creates a script task with the visible form values', async () => {
     const fetchMock = createFetchMock()
     vi.stubGlobal('fetch', fetchMock)

frontend/src/api/client.ts

@@ -24,6 +24,8 @@ export type InterpreterKind = components['schemas']['InterpreterKind']
 export type DirectoryEntry = components['schemas']['DirectoryEntry']
 export type DirectoryListingResponse =
   components['schemas']['DirectoryListingResponse']
+export type TaskStats = components['schemas']['TaskStatsResponse']
+export type ScheduledTask = components['schemas']['ScheduledTaskResponse']
 
 export interface TaskFilters {
   q?: string
@@ -77,20 +79,27 @@ async function requestJson<T>(
   path: string,
   init: RequestInit = {},
 ): Promise<T> {
-  const headers = new Headers(init.headers)
-  headers.set('Accept', 'application/json')
   const method = (init.method ?? 'GET').toUpperCase()
-  if (init.body) {
-    headers.set('Content-Type', 'application/json')
-  }
-  if (!['GET', 'HEAD', 'OPTIONS'].includes(method)) {
-    headers.set('X-TaskPilot-Token', await fetchSessionToken())
+  const mutating = !['GET', 'HEAD', 'OPTIONS'].includes(method)
+
+  const send = async (): Promise<Response> => {
+    const headers = new Headers(init.headers)
+    headers.set('Accept', 'application/json')
+    if (init.body) {
+      headers.set('Content-Type', 'application/json')
+    }
+    if (mutating) {
+      headers.set('X-TaskPilot-Token', await fetchSessionToken())
+    }
+    return fetch(path, { ...init, headers })
   }
 
-  const response = await fetch(path, {
-    ...init,
-    headers,
-  })
+  let response = await send()
+  if (mutating && response.status === 403) {
+    // 后端重启会轮换管理令牌：丢弃缓存后重试一次。
+    invalidateSessionToken()
+    response = await send()
+  }
 
   if (!response.ok) {
     let body: ErrorResponse | undefined
@@ -108,15 +117,34 @@ async function requestJson<T>(
   return (await response.json()) as T
 }
 
+let cachedSessionToken: string | null = null
+let pendingSessionToken: Promise<string> | null = null
+
+export function invalidateSessionToken(): void {
+  cachedSessionToken = null
+}
+
 async function fetchSessionToken(): Promise<string> {
-  const response = await fetch('/api/v1/session', {
-    headers: { Accept: 'application/json' },
-  })
-  if (!response.ok) {
-    throw new ApiRequestError(response.status)
+  if (cachedSessionToken) {
+    return cachedSessionToken
   }
-  const session = (await response.json()) as SessionResponse
-  return session.token
+  if (!pendingSessionToken) {
+    pendingSessionToken = fetch('/api/v1/session', {
+      headers: { Accept: 'application/json' },
+    })
+      .then(async (response) => {
+        if (!response.ok) {
+          throw new ApiRequestError(response.status)
+        }
+        const session = (await response.json()) as SessionResponse
+        cachedSessionToken = session.token
+        return session.token
+      })
+      .finally(() => {
+        pendingSessionToken = null
+      })
+  }
+  return pendingSessionToken
 }
 
 function withQuery(path: string, values: object): string {
@@ -265,3 +293,13 @@ export function listDirectories(
     { signal },
   )
 }
+
+/** 仪表盘计数：一次请求拿到全部指标。 */
+export function fetchStats(signal?: AbortSignal): Promise<TaskStats> {
+  return requestJson<TaskStats>('/api/v1/stats', { signal })
+}
+
+/** 已启用任务的下次触发时间。 */
+export function fetchSchedule(signal?: AbortSignal): Promise<ScheduledTask[]> {
+  return requestJson<ScheduledTask[]>('/api/v1/schedule', { signal })
+}

frontend/src/api/generated.ts

@@ -132,6 +132,22 @@ export interface paths {
         patch?: never;
         trace?: never;
     };
+    "/api/v1/schedule": {
+        parameters: {
+            query?: never;
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        get: operations["list_schedule"];
+        put?: never;
+        post?: never;
+        delete?: never;
+        options?: never;
+        head?: never;
+        patch?: never;
+        trace?: never;
+    };
     "/api/v1/session": {
         parameters: {
             query?: never;
@@ -148,6 +164,22 @@ export interface paths {
         patch?: never;
         trace?: never;
     };
+    "/api/v1/stats": {
+        parameters: {
+            query?: never;
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        get: operations["task_stats"];
+        put?: never;
+        post?: never;
+        delete?: never;
+        options?: never;
+        head?: never;
+        patch?: never;
+        trace?: never;
+    };
     "/api/v1/system/directories": {
         parameters: {
             query?: never;
@@ -338,6 +370,15 @@ export interface components {
         RunStatus: "queued" | "running" | "succeeded" | "failed" | "timed_out" | "cancelled" | "skipped";
         /** @enum {string} */
         RunTrigger: "schedule" | "manual" | "retry";
+        /** @description 已注册调度的任务及其下次触发时间。 */
+        ScheduledTaskResponse: {
+            /**
+             * Format: date-time
+             * @description 下次触发时间；调度正在重建时可能为空
+             */
+            next_run_at?: string | null;
+            task_id: string;
+        };
         SessionResponse: {
             /** @description Random per-process token required for mutating browser requests. */
             token: string;
@@ -427,6 +468,39 @@ export interface components {
             task_id: string;
             trigger: components["schemas"]["RunTrigger"];
         };
+        /** @description 仪表盘指标：一次请求拿到全部计数，避免为每个指标各发一次列表查询。 */
+        TaskStatsResponse: {
+            /**
+             * Format: int64
+             * @description 已启用任务数
+             */
+            enabled: number;
+            /**
+             * Format: int64
+             * @description HTTP 类任务数
+             */
+            http: number;
+            /**
+             * Format: int64
+             * @description 进程类任务数
+             */
+            process: number;
+            /**
+             * Format: int64
+             * @description 当前正在执行的任务数
+             */
+            running: number;
+            /**
+             * Format: int64
+             * @description 脚本类任务数
+             */
+            script: number;
+            /**
+             * Format: int64
+             * @description 任务总数
+             */
+            total: number;
+        };
         UpdateTaskRequest: {
             action: components["schemas"]["TaskAction"];
             concurrency_policy?: components["schemas"]["ConcurrencyPolicy"];
@@ -718,6 +792,26 @@ export interface operations {
             };
         };
     };
+    list_schedule: {
+        parameters: {
+            query?: never;
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        requestBody?: never;
+        responses: {
+            /** @description Next trigger time per enabled task */
+            200: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content: {
+                    "application/json": components["schemas"]["ScheduledTaskResponse"][];
+                };
+            };
+        };
+    };
     session: {
         parameters: {
             query?: never;
@@ -738,6 +832,26 @@ export interface operations {
             };
         };
     };
+    task_stats: {
+        parameters: {
+            query?: never;
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        requestBody?: never;
+        responses: {
+            /** @description Dashboard counters */
+            200: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content: {
+                    "application/json": components["schemas"]["TaskStatsResponse"];
+                };
+            };
+        };
+    };
     list_directories: {
         parameters: {
             query?: {

frontend/src/lib/format.ts

@@ -17,6 +17,21 @@ export function formatDateTime(value: string | null | undefined): string {
   return Number.isNaN(date.getTime()) ? '--' : dateTimeFormatter.format(date)
 }
 
+const shortDateTimeFormatter = new Intl.DateTimeFormat('zh-CN', {
+  month: '2-digit',
+  day: '2-digit',
+  hour: '2-digit',
+  minute: '2-digit',
+})
+
+export function formatShortDateTime(value: string | null | undefined): string {
+  if (!value) {
+    return '--'
+  }
+  const date = new Date(value)
+  return Number.isNaN(date.getTime()) ? '--' : shortDateTimeFormatter.format(date)
+}
+
 export function formatDuration(value: number | null | undefined): string {
   if (value === null || value === undefined) {
     return '--'

frontend/src/pages/TaskDashboard.tsx

@@ -10,6 +10,8 @@ import {
   createTask,
   deleteTask,
   fetchHealth,
+  fetchSchedule,
+  fetchStats,
   listTasks,
   runTask,
   setTaskEnabled,
@@ -24,7 +26,7 @@ import {
   EnabledBadge,
 } from '../components/StatusBadge'
 import { TaskEditorModal } from '../components/TaskEditorModal'
-import { actionTypeLabel } from '../lib/format'
+import { actionTypeLabel, formatShortDateTime } from '../lib/format'
 import {
   type TaskFormValues,
   valuesToCreateRequest,
@@ -75,23 +77,19 @@ export function TaskDashboard() {
     queryFn: ({ signal }) => listTasks(filters, signal),
     placeholderData: keepPreviousData,
   })
-  const totalTasksQuery = useQuery({
-    queryKey: ['tasks', 'summary', 'total'],
-    queryFn: ({ signal }) => listTasks({ page: 1, page_size: 1 }, signal),
+  const statsQuery = useQuery({
+    queryKey: ['stats'],
+    queryFn: ({ signal }) => fetchStats(signal),
+    refetchInterval: 15_000,
   })
-  const enabledTasksQuery = useQuery({
-    queryKey: ['tasks', 'summary', 'enabled'],
-    queryFn: ({ signal }) =>
-      listTasks({ enabled: true, page: 1, page_size: 1 }, signal),
-  })
-  const scriptTasksQuery = useQuery({
-    queryKey: ['tasks', 'summary', 'script'],
-    queryFn: ({ signal }) =>
-      listTasks(
-        { action_type: 'script', page: 1, page_size: 1 },
-        signal,
-      ),
+  const scheduleQuery = useQuery({
+    queryKey: ['schedule'],
+    queryFn: ({ signal }) => fetchSchedule(signal),
+    refetchInterval: 15_000,
   })
+  const nextRuns = new Map(
+    (scheduleQuery.data ?? []).map((entry) => [entry.task_id, entry.next_run_at]),
+  )
 
   const saveMutation = useMutation({
     mutationFn: ({
@@ -232,18 +230,18 @@ export function TaskDashboard() {
       <section className="metrics-grid" aria-label="任务统计">
         <MetricCard
           label="已托管任务"
-          value={totalTasksQuery.data?.total}
-          loading={totalTasksQuery.isPending}
+          value={statsQuery.data?.total}
+          loading={statsQuery.isPending}
         />
         <MetricCard
-          label="正常运行中"
-          value={enabledTasksQuery.data?.total}
-          loading={enabledTasksQuery.isPending}
+          label="运行中任务"
+          value={statsQuery.data?.running}
+          loading={statsQuery.isPending}
         />
         <MetricCard
           label="可用脚本"
-          value={scriptTasksQuery.data?.total}
-          loading={scriptTasksQuery.isPending}
+          value={statsQuery.data?.script}
+          loading={statsQuery.isPending}
         />
         <article className="metric-card">
           <span>Rust 引擎</span>
@@ -407,6 +405,13 @@ export function TaskDashboard() {
                         <td>
                           <code>{task.cron}</code>
                           <div className="cell-note">{task.timezone}</div>
+                          <div className="cell-note">
+                            {task.enabled
+                              ? nextRuns.get(task.id)
+                                ? `下次 ${formatShortDateTime(nextRuns.get(task.id))}`
+                                : '调度中…'
+                              : '未调度'}
+                          </div>
                         </td>
                         <td>
                           <span className="type-badge">
@@ -573,5 +578,7 @@ async function invalidateTaskData(queryClient: ReturnType<typeof useQueryClient>
   await Promise.all([
     queryClient.invalidateQueries({ queryKey: ['tasks'] }),
     queryClient.invalidateQueries({ queryKey: ['task-runs'] }),
+    queryClient.invalidateQueries({ queryKey: ['stats'] }),
+    queryClient.invalidateQueries({ queryKey: ['schedule'] }),
   ])
 }