diff --git a/app/components/storage/BackupJobTable.vue b/app/components/storage/BackupJobTable.vue
index d755b32..2c419b3 100644
--- a/app/components/storage/BackupJobTable.vue
+++ b/app/components/storage/BackupJobTable.vue
@@ -142,7 +142,7 @@ function formatTime(value: string) {
               {{ t('storage.backup.colProgress') }}
             </th>
             <th class="px-4 py-3 font-medium sm:px-5">
-              {{ t('storage.backup.colCreated') }}
+              {{ t('storage.backup.colUpdated') }}
             </th>
             <th class="px-4 py-3 font-medium sm:px-5">
               {{ t('storage.backup.colActions') }}
@@ -203,7 +203,7 @@ function formatTime(value: string) {
               </div>
             </td>
             <td class="px-4 py-3.5 whitespace-nowrap text-xs text-muted sm:px-5">
-              {{ formatTime(job.createdAt) }}
+              {{ formatTime(job.updatedAt || job.finishedAt || job.createdAt) }}
             </td>
             <td class="px-4 py-3.5 sm:px-5">
               <div class="flex flex-wrap gap-1.5">
diff --git a/app/types/backup.ts b/app/types/backup.ts
index c617419..24dc4ed 100644
--- a/app/types/backup.ts
+++ b/app/types/backup.ts
@@ -15,6 +15,7 @@ export interface BackupJobItem {
   downloadable: boolean
   error: string | null
   createdAt: string
+  updatedAt: string
   finishedAt: string | null
 }
 
diff --git a/i18n/locales/en.json b/i18n/locales/en.json
index 7fbbcf9..5e12c42 100644
--- a/i18n/locales/en.json
+++ b/i18n/locales/en.json
@@ -745,6 +745,7 @@
       "progressUnitObjects": "storage objects",
       "colMessage": "Message",
       "colCreated": "Created",
+      "colUpdated": "Updated",
       "colActions": "Actions",
       "jobTypeExport": "Site export",
       "jobTypeRestore": "Site restore",
diff --git a/i18n/locales/zh-CN.json b/i18n/locales/zh-CN.json
index fa7574e..debd04e 100644
--- a/i18n/locales/zh-CN.json
+++ b/i18n/locales/zh-CN.json
@@ -745,6 +745,7 @@
       "progressUnitObjects": "存储对象",
       "colMessage": "说明",
       "colCreated": "创建时间",
+      "colUpdated": "更新时间",
       "colActions": "操作",
       "jobTypeExport": "站点导出",
       "jobTypeRestore": "站点恢复",
diff --git a/server/utils/backup/api.ts b/server/utils/backup/api.ts
index 639ee79..02b5304 100644
--- a/server/utils/backup/api.ts
+++ b/server/utils/backup/api.ts
@@ -26,6 +26,7 @@ export function serializeBackupJob(job: BackupJob) {
     ),
     error: job.error,
     createdAt: job.createdAt,
+    updatedAt: job.updatedAt,
     finishedAt: job.finishedAt
   }
 }
diff --git a/server/utils/backup/jobs.ts b/server/utils/backup/jobs.ts
index 941bf8e..8da3227 100644
--- a/server/utils/backup/jobs.ts
+++ b/server/utils/backup/jobs.ts
@@ -17,6 +17,7 @@ export interface BackupJob {
   outputPath: string | null
   error: string | null
   createdAt: string
+  updatedAt: string
   finishedAt: string | null
 }
 
@@ -32,6 +33,7 @@ interface BackupJobRow {
   output_path: string | null
   error: string | null
   created_at: string
+  updated_at: string
   finished_at: string | null
 }
 
@@ -55,6 +57,7 @@ function rowToJob(row: BackupJobRow): BackupJob {
     outputPath: row.output_path,
     error: row.error,
     createdAt: row.created_at,
+    updatedAt: row.updated_at,
     finishedAt: row.finished_at
   }
 }
@@ -69,7 +72,7 @@ export function getRunningBackupJob(userId?: number): BackupJob | null {
   ensureBackupSchema()
   const row = getDb().prepare(`
     SELECT id, user_id, type, status, progress, total, message, payload_json,
-           output_path, error, created_at, finished_at
+           output_path, error, created_at, updated_at, finished_at
     FROM backup_jobs
     WHERE status = 'running'${userId === undefined ? '' : ' AND user_id = ?'}
     LIMIT 1
@@ -81,7 +84,7 @@ export function getActiveBackupJob(userId?: number): BackupJob | null {
   ensureBackupSchema()
   const row = getDb().prepare(`
     SELECT id, user_id, type, status, progress, total, message, payload_json,
-           output_path, error, created_at, finished_at
+           output_path, error, created_at, updated_at, finished_at
     FROM backup_jobs
     WHERE status IN ('pending', 'running')${userId === undefined ? '' : ' AND user_id = ?'}
     ORDER BY created_at DESC
@@ -105,8 +108,8 @@ export function createBackupJob(input: {
 
   getDb().prepare(`
     INSERT INTO backup_jobs
-      (id, user_id, type, status, progress, total, message, payload_json, output_path, error, created_at, finished_at)
-    VALUES (?, ?, ?, 'pending', 0, ?, ?, ?, NULL, NULL, ?, NULL)
+      (id, user_id, type, status, progress, total, message, payload_json, output_path, error, created_at, updated_at, finished_at)
+    VALUES (?, ?, ?, 'pending', 0, ?, ?, ?, NULL, NULL, ?, ?, NULL)
   `).run(
     id,
     userId,
@@ -114,6 +117,7 @@ export function createBackupJob(input: {
     input.total ?? 0,
     input.message ?? '',
     payloadJson,
+    now,
     now
   )
 
@@ -124,7 +128,7 @@ export function getBackupJob(id: string, userId?: number): BackupJob | null {
   ensureBackupSchema()
   const row = getDb().prepare(`
     SELECT id, user_id, type, status, progress, total, message, payload_json,
-           output_path, error, created_at, finished_at
+           output_path, error, created_at, updated_at, finished_at
     FROM backup_jobs
     WHERE id = ?${userId === undefined ? '' : ' AND user_id = ?'}
   `).get(...(userId === undefined ? [id] : [id, userId])) as BackupJobRow | undefined
@@ -156,7 +160,7 @@ export function listBackupJobsPage(
   const total = countBackupJobs(userId)
   const rows = getDb().prepare(`
     SELECT id, user_id, type, status, progress, total, message, payload_json,
-           output_path, error, created_at, finished_at
+           output_path, error, created_at, updated_at, finished_at
     FROM backup_jobs
     ${userId === undefined ? '' : 'WHERE user_id = ?'}
     ORDER BY created_at DESC
@@ -169,7 +173,7 @@ export function listAllBackupJobsForUser(userId: number): BackupJob[] {
   ensureBackupSchema()
   const rows = getDb().prepare(`
     SELECT id, user_id, type, status, progress, total, message, payload_json,
-           output_path, error, created_at, finished_at
+           output_path, error, created_at, updated_at, finished_at
     FROM backup_jobs
     WHERE user_id = ?
     ORDER BY created_at DESC
@@ -197,8 +201,8 @@ export function restoreBackupJobsAfterReplace(preserved: BackupJob[]): void {
     db.prepare('DELETE FROM backup_jobs').run()
     const insert = db.prepare(`
       INSERT INTO backup_jobs
-        (id, user_id, type, status, progress, total, message, payload_json, output_path, error, created_at, finished_at)
-      VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+        (id, user_id, type, status, progress, total, message, payload_json, output_path, error, created_at, updated_at, finished_at)
+      VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
     `)
     for (const job of preserved) {
       insert.run(
@@ -213,6 +217,7 @@ export function restoreBackupJobsAfterReplace(preserved: BackupJob[]): void {
         job.outputPath,
         job.error,
         job.createdAt,
+        job.updatedAt,
         job.finishedAt
       )
     }
@@ -232,9 +237,10 @@ export function recoverInterruptedBackupJobs(): number {
     SET status = 'failed',
         error = '任务中断（服务重启或异常退出）',
         message = '任务已中断，请重试',
+        updated_at = ?,
         finished_at = ?
     WHERE status = 'running'
-  `).run(finishedAt)
+  `).run(finishedAt, finishedAt)
   return Number(result.changes ?? 0)
 }
 
@@ -263,13 +269,14 @@ export function updateBackupJob(
     payload: patch.payload ?? current.payload,
     outputPath: patch.outputPath !== undefined ? patch.outputPath : current.outputPath,
     error: patch.error !== undefined ? patch.error : current.error,
+    updatedAt: new Date().toISOString(),
     finishedAt: patch.finishedAt !== undefined ? patch.finishedAt : current.finishedAt
   }
 
   getDb().prepare(`
     UPDATE backup_jobs
     SET status = ?, progress = ?, total = ?, message = ?, payload_json = ?,
-        output_path = ?, error = ?, finished_at = ?
+        output_path = ?, error = ?, updated_at = ?, finished_at = ?
     WHERE id = ?
   `).run(
     next.status,
@@ -279,11 +286,25 @@ export function updateBackupJob(
     JSON.stringify(next.payload),
     next.outputPath,
     next.error,
+    next.updatedAt,
     next.finishedAt,
     id
   )
 }
 
+/** Update job data without changing its last activity timestamp. */
+export function updateBackupJobPayload(
+  id: string,
+  payload: Record<string, unknown>
+): void {
+  ensureBackupSchema()
+  getDb().prepare(`
+    UPDATE backup_jobs
+    SET payload_json = ?
+    WHERE id = ?
+  `).run(JSON.stringify(payload), id)
+}
+
 export function markJobRunning(id: string, message?: string): void {
   updateBackupJob(id, {
     status: 'running',
diff --git a/server/utils/backup/runner.ts b/server/utils/backup/runner.ts
index f49d03c..4fed386 100644
--- a/server/utils/backup/runner.ts
+++ b/server/utils/backup/runner.ts
@@ -8,6 +8,7 @@ import {
   markJobFailed,
   markJobRunning,
   recoverInterruptedBackupJobs,
+  updateBackupJobPayload,
   type BackupJob
 } from './jobs'
 import {
@@ -149,22 +150,41 @@ export function resumeSiteSyncJob(
   userId?: number | null
 ): BackupJob {
   claimJobSlot()
-  const job = getBackupJob(jobId, userId ?? undefined)
+  const previousJob = getBackupJob(jobId, userId ?? undefined)
   if (
-    !job
-    || job.type !== 'site_sync'
-    || job.status !== 'failed'
-    || job.payload.resumable !== true
+    !previousJob
+    || previousJob.type !== 'site_sync'
+    || previousJob.status !== 'failed'
+    || previousJob.payload.resumable !== true
   ) {
     throw new Error('SITE_SYNC_JOB_NOT_RESUMABLE')
   }
-  const targetBaseUrl = typeof job.payload.targetBaseUrl === 'string'
-    ? job.payload.targetBaseUrl
+  const targetBaseUrl = typeof previousJob.payload.targetBaseUrl === 'string'
+    ? previousJob.payload.targetBaseUrl
     : ''
-  const conflictMode = job.payload.conflictMode === 'skip' ? 'skip' : 'overwrite'
-  const direction = job.payload.direction === 'pull' ? 'pull' : 'push'
+  const conflictMode = previousJob.payload.conflictMode === 'skip'
+    ? 'skip'
+    : 'overwrite'
+  const direction = previousJob.payload.direction === 'pull' ? 'pull' : 'push'
   if (!targetBaseUrl) throw new Error('SITE_SYNC_JOB_NOT_RESUMABLE')
 
+  const job = createBackupJob({
+    type: 'site_sync',
+    userId: previousJob.userId,
+    total: previousJob.total,
+    message: `继续任务 ${previousJob.id}…`,
+    payload: {
+      ...previousJob.payload,
+      resumedFromJobId: previousJob.id,
+      resumedAt: new Date().toISOString(),
+      cancelled: false
+    }
+  })
+  updateBackupJobPayload(previousJob.id, {
+    ...previousJob.payload,
+    resumable: false,
+    supersededByJobId: job.id
+  })
   registerSiteSyncToken(job.id, token)
   scheduleBackupJob(job, () => runSiteSyncJob(job.id, {
     targetBaseUrl,
diff --git a/server/utils/backup/schema.ts b/server/utils/backup/schema.ts
index 3c50812..b850c80 100644
--- a/server/utils/backup/schema.ts
+++ b/server/utils/backup/schema.ts
@@ -24,11 +24,12 @@ function migrateBackupJobTypes(): void {
       output_path TEXT,
       error TEXT,
       created_at TEXT NOT NULL,
+      updated_at TEXT NOT NULL,
       finished_at TEXT
     );
     INSERT INTO backup_jobs_new
-      (id, user_id, type, status, progress, total, message, payload_json, output_path, error, created_at, finished_at)
-    SELECT id, user_id, type, status, progress, total, message, payload_json, output_path, error, created_at, finished_at
+      (id, user_id, type, status, progress, total, message, payload_json, output_path, error, created_at, updated_at, finished_at)
+    SELECT id, user_id, type, status, progress, total, message, payload_json, output_path, error, created_at, COALESCE(updated_at, created_at), finished_at
     FROM backup_jobs;
     DROP TABLE backup_jobs;
     ALTER TABLE backup_jobs_new RENAME TO backup_jobs;
@@ -53,6 +54,7 @@ export function ensureBackupSchema(): void {
       output_path TEXT,
       error TEXT,
       created_at TEXT NOT NULL,
+      updated_at TEXT NOT NULL,
       finished_at TEXT
     );
     CREATE INDEX IF NOT EXISTS idx_backup_jobs_created_at
@@ -65,6 +67,9 @@ export function ensureBackupSchema(): void {
   if (!columns.some(column => column.name === 'user_id')) {
     getDb().exec('ALTER TABLE backup_jobs ADD COLUMN user_id INTEGER')
   }
+  if (!columns.some(column => column.name === 'updated_at')) {
+    getDb().exec('ALTER TABLE backup_jobs ADD COLUMN updated_at TEXT')
+  }
   getDb().exec(`
     CREATE INDEX IF NOT EXISTS idx_backup_jobs_user_created
       ON backup_jobs(user_id, created_at DESC);
@@ -74,6 +79,13 @@ export function ensureBackupSchema(): void {
     )
     WHERE user_id IS NULL
       AND EXISTS (SELECT 1 FROM users WHERE role = 'admin');
+    UPDATE backup_jobs
+    SET updated_at = COALESCE(finished_at, created_at)
+    WHERE updated_at IS NULL;
+    UPDATE backup_jobs
+    SET updated_at = finished_at
+    WHERE finished_at IS NOT NULL
+      AND updated_at = created_at;
   `)
   migrateBackupJobTypes()
 }
diff --git a/server/utils/site-sync/runner.test.ts b/server/utils/site-sync/runner.test.ts
index a7a2f21..8947a79 100644
--- a/server/utils/site-sync/runner.test.ts
+++ b/server/utils/site-sync/runner.test.ts
@@ -62,7 +62,11 @@ describe('fetchSiteSyncJson', () => {
   it('stops retrying immediately when the job is cancelled', async () => {
     const jobId = 'cancel-test'
     beginJobCancellationScope(jobId)
-    const operation = vi.fn().mockRejectedValue(new Error('connection reset'))
+    const operation = vi.fn().mockImplementation(() => (
+      new Promise((_, reject) => {
+        setTimeout(() => reject(new Error('connection reset')), 1000)
+      })
+    ))
     const result = retrySiteSyncOperation(operation, getJobAbortSignal(jobId))
 
     setTimeout(() => requestJobCancellation(jobId), 25)
@@ -71,4 +75,40 @@ describe('fetchSiteSyncJson', () => {
     expect(operation).toHaveBeenCalledTimes(1)
     endJobCancellationScope(jobId)
   })
+
+  it('reports every retry attempt and backoff to the job status', async () => {
+    const fetchMock = vi.fn()
+      .mockRejectedValueOnce(new DOMException('timed out', 'TimeoutError'))
+      .mockResolvedValueOnce(new Response('{"ok":true}', {
+        status: 200,
+        headers: { 'Content-Type': 'application/json' }
+      }))
+    vi.stubGlobal('fetch', fetchMock)
+    const statuses: Array<{
+      attempt: number
+      phase: string
+      delayMs?: number
+    }> = []
+
+    await expect(fetchSiteSyncJson(
+      'http://target/api',
+      'token',
+      undefined,
+      undefined,
+      status => statuses.push(status)
+    )).resolves.toEqual({ ok: true })
+
+    expect(
+      statuses
+        .filter(status => status.phase !== 'countdown')
+        .map(status => `${status.phase}:${status.attempt}`)
+    ).toEqual([
+      'attempt:1',
+      'retry:1',
+      'attempt:2'
+    ])
+    expect(
+      statuses.find(status => status.phase === 'retry')?.delayMs
+    ).toBe(0)
+  })
 })
diff --git a/server/utils/site-sync/runner.ts b/server/utils/site-sync/runner.ts
index 4c90c41..287db4a 100644
--- a/server/utils/site-sync/runner.ts
+++ b/server/utils/site-sync/runner.ts
@@ -1,4 +1,8 @@
 import { basename } from 'node:path'
+import {
+  Agent,
+  fetch as undiciFetch
+} from 'undici'
 import type { Readable } from 'node:stream'
 import { contentTypeFromKey } from '../content-type'
 import {
@@ -26,7 +30,6 @@ import {
 import {
   createJobCancelledError,
   getJobAbortSignal,
-  getJobOperationSignal,
   isJobCancellationRequested,
   isJobCancelledError,
   throwIfJobCancellationRequested
@@ -62,8 +65,32 @@ export function registerSiteSyncToken(jobId: string, token: string): void {
   tokens.set(jobId, token)
 }
 
-const SITE_SYNC_JSON_TIMEOUT_MS = 2 * 60 * 1000
-const SITE_SYNC_OBJECT_TIMEOUT_MS = 15 * 60 * 1000
+const SITE_SYNC_CONNECT_TIMEOUT_MS = 3 * 1000
+const SITE_SYNC_RESPONSE_IDLE_TIMEOUT_MS = 3 * 1000
+const SITE_SYNC_UPLOAD_HEADERS_TIMEOUT_MS = 10 * 60 * 1000
+
+interface SiteSyncAgents {
+  upload: Agent
+  object: Agent
+}
+
+const agents = (globalThis as typeof globalThis & {
+  __pichostSiteSyncAgents?: SiteSyncAgents
+}).__pichostSiteSyncAgents ?? {
+  upload: new Agent({
+    connect: { timeout: SITE_SYNC_CONNECT_TIMEOUT_MS },
+    headersTimeout: SITE_SYNC_UPLOAD_HEADERS_TIMEOUT_MS,
+    bodyTimeout: SITE_SYNC_RESPONSE_IDLE_TIMEOUT_MS
+  }),
+  object: new Agent({
+    connect: { timeout: SITE_SYNC_CONNECT_TIMEOUT_MS },
+    headersTimeout: SITE_SYNC_RESPONSE_IDLE_TIMEOUT_MS,
+    bodyTimeout: SITE_SYNC_RESPONSE_IDLE_TIMEOUT_MS
+  })
+}
+;(globalThis as typeof globalThis & {
+  __pichostSiteSyncAgents?: SiteSyncAgents
+}).__pichostSiteSyncAgents = agents
 
 async function streamToBuffer(
   stream: Readable,
@@ -84,7 +111,10 @@ function targetUrl(baseUrl: string, path: string): string {
   return `${baseUrl.replace(/\/+$/, '')}${path}`
 }
 
-async function responseError(response: Response): Promise<Error> {
+async function responseError(response: {
+  status: number
+  json: () => Promise<unknown>
+}): Promise<Error> {
   const payload = await response.json().catch(() => null) as {
     message?: string
     statusMessage?: string
@@ -92,11 +122,60 @@ async function responseError(response: Response): Promise<Error> {
   return new Error(payload?.message || payload?.statusMessage || `目标站点返回 ${response.status}`)
 }
 
+function parseResponseErrorText(
+  text: string,
+  status: number
+): Error {
+  try {
+    const payload = JSON.parse(text) as {
+      message?: string
+      statusMessage?: string
+    }
+    return new Error(
+      payload.message
+      || payload.statusMessage
+      || `目标站点返回 ${status}`
+    )
+  } catch {
+    return new Error(`目标站点返回 ${status}`)
+  }
+}
+
 const SITE_SYNC_MAX_ATTEMPTS = 3
 
+export interface SiteSyncRetryStatus {
+  attempt: number
+  maxAttempts: number
+  phase: 'attempt' | 'countdown' | 'retry'
+  delayMs?: number
+  remainingMs?: number
+  error?: Error
+}
+
+function formatRetryStatus(
+  step: string,
+  status: SiteSyncRetryStatus
+): string {
+  if (status.phase === 'attempt') {
+    return `${step}（第 ${status.attempt}/${status.maxAttempts} 次）`
+  }
+  if (status.phase === 'countdown') {
+    const seconds = Math.max(
+      1,
+      Math.ceil((status.remainingMs ?? 0) / 1000)
+    )
+    return `${step}（第 ${status.attempt}/${status.maxAttempts} 次）· 连接倒计时 ${seconds}s`
+  }
+  if ((status.delayMs ?? 0) < 1000) {
+    return `${step}第 ${status.attempt}/${status.maxAttempts} 次无响应，即将重试：${status.error?.message ?? '连接失败'}`
+  }
+  const seconds = Math.max(1, Math.round((status.delayMs ?? 0) / 1000))
+  return `${step}第 ${status.attempt}/${status.maxAttempts} 次失败，${seconds} 秒后重试：${status.error?.message ?? '连接失败'}`
+}
+
 function normalizeSiteSyncError(error: Error): Error {
-  if (error.name === 'TimeoutError') {
-    return new Error('目标站点连接超时或无响应')
+  if (/timeout/i.test(error.name) || /timed out|idle for too long/i.test(error.message)) {
+    return new Error('目标站点在 3 秒内未响应')
   }
   if (error instanceof TypeError && /fetch failed|terminated/i.test(error.message)) {
     return new Error('目标站点无法连接')
@@ -106,17 +185,57 @@ function normalizeSiteSyncError(error: Error): Error {
 
 export async function retrySiteSyncOperation<T>(
   operation: () => Promise<T>,
-  signal?: AbortSignal
+  signal?: AbortSignal,
+  onStatus?: (status: SiteSyncRetryStatus) => void
 ): Promise<T> {
   if (signal?.aborted) throw createJobCancelledError()
   let lastError: Error | null = null
   for (let attempt = 1; attempt <= SITE_SYNC_MAX_ATTEMPTS; attempt++) {
+    let countdownTimer: ReturnType<typeof setInterval> | null = null
     try {
+      onStatus?.({
+        attempt,
+        maxAttempts: SITE_SYNC_MAX_ATTEMPTS,
+        phase: 'attempt'
+      })
+      if (onStatus) {
+        let remainingMs = SITE_SYNC_CONNECT_TIMEOUT_MS
+        onStatus({
+          attempt,
+          maxAttempts: SITE_SYNC_MAX_ATTEMPTS,
+          phase: 'countdown',
+          remainingMs
+        })
+        countdownTimer = setInterval(() => {
+          remainingMs -= 1000
+          if (remainingMs <= 0) {
+            if (countdownTimer) clearInterval(countdownTimer)
+            countdownTimer = null
+            return
+          }
+          onStatus({
+            attempt,
+            maxAttempts: SITE_SYNC_MAX_ATTEMPTS,
+            phase: 'countdown',
+            remainingMs
+          })
+        }, 1000)
+      }
       return await operation()
     } catch (error) {
+      if (countdownTimer) clearInterval(countdownTimer)
+      countdownTimer = null
       if (signal?.aborted) throw createJobCancelledError()
       lastError = error instanceof Error ? error : new Error('两站点同步失败')
       if (attempt < SITE_SYNC_MAX_ATTEMPTS) {
+        const delayMs = 0
+        onStatus?.({
+          attempt,
+          maxAttempts: SITE_SYNC_MAX_ATTEMPTS,
+          phase: 'retry',
+          delayMs,
+          error: normalizeSiteSyncError(lastError)
+        })
         await new Promise<void>((resolve, reject) => {
           const onAbort = () => {
             clearTimeout(timer)
@@ -125,10 +244,12 @@ export async function retrySiteSyncOperation<T>(
           const timer = setTimeout(() => {
             signal?.removeEventListener('abort', onAbort)
             resolve()
-          }, attempt * 500)
+          }, delayMs)
           signal?.addEventListener('abort', onAbort, { once: true })
         })
       }
+    } finally {
+      if (countdownTimer) clearInterval(countdownTimer)
     }
   }
   throw lastError
@@ -141,34 +262,124 @@ async function fetchSiteSyncJsonOnce<T>(
   token: string,
   init?: RequestInit
 ): Promise<T> {
-  const response = await fetch(url, {
-    ...init,
-    headers: {
-      'Auth-Token': token,
-      ...(init?.headers ?? {})
+  const connectionController = new AbortController()
+  const onAbort = () => connectionController.abort(createJobCancelledError())
+  init?.signal?.addEventListener('abort', onAbort, { once: true })
+  const timeout = setTimeout(() => {
+    connectionController.abort(new DOMException(
+      'Target connection or TLS handshake timed out',
+      'TimeoutError'
+    ))
+  }, SITE_SYNC_CONNECT_TIMEOUT_MS)
+
+  try {
+    const response = await fetch(url, {
+      ...init,
+      headers: {
+        'Auth-Token': token,
+        ...(init?.headers ?? {})
+      },
+      signal: init?.signal
+        ? AbortSignal.any([init.signal, connectionController.signal])
+        : connectionController.signal
+    })
+    clearTimeout(timeout)
+
+    if (!response.body) {
+      const text = await response.text()
+      if (!response.ok) throw parseResponseErrorText(text, response.status)
+      return JSON.parse(text) as T
     }
+
+    const reader = response.body.getReader()
+    const decoder = new TextDecoder()
+    let text = ''
+    try {
+      while (true) {
+        const chunk = await readChunkWithIdleTimeout(
+          reader,
+          init?.signal ?? undefined
+        )
+        if (chunk.done) break
+        text += decoder.decode(chunk.value, { stream: true })
+      }
+      text += decoder.decode()
+    } finally {
+      reader.releaseLock()
+    }
+    if (!response.ok) throw parseResponseErrorText(text, response.status)
+    return JSON.parse(text) as T
+  } finally {
+    clearTimeout(timeout)
+    init?.signal?.removeEventListener('abort', onAbort)
+  }
+}
+
+async function readChunkWithIdleTimeout(
+  reader: ReadableStreamDefaultReader<Uint8Array>,
+  signal?: AbortSignal
+): Promise<ReadableStreamReadResult<Uint8Array>> {
+  if (signal?.aborted) {
+    await reader.cancel().catch(() => {})
+    throw createJobCancelledError()
+  }
+
+  return new Promise((resolve, reject) => {
+    let settled = false
+    const cleanup = () => {
+      clearTimeout(timer)
+      signal?.removeEventListener('abort', onAbort)
+    }
+    const onAbort = () => {
+      if (settled) return
+      settled = true
+      cleanup()
+      void reader.cancel().catch(() => {})
+      reject(createJobCancelledError())
+    }
+    const timer = setTimeout(() => {
+      if (settled) return
+      settled = true
+      cleanup()
+      void reader.cancel().catch(() => {})
+      reject(new DOMException(
+        'Target response body was idle for too long',
+        'TimeoutError'
+      ))
+    }, SITE_SYNC_RESPONSE_IDLE_TIMEOUT_MS)
+    signal?.addEventListener('abort', onAbort, { once: true })
+
+    reader.read().then(
+      (result) => {
+        if (settled) return
+        settled = true
+        cleanup()
+        resolve(result)
+      },
+      (error) => {
+        if (settled) return
+        settled = true
+        cleanup()
+        reject(error)
+      }
+    )
   })
-  if (!response.ok) throw await responseError(response)
-  return await response.json() as T
 }
 
 export async function fetchSiteSyncJson<T>(
   url: string,
   token: string,
   init?: RequestInit,
-  signal?: AbortSignal
+  signal?: AbortSignal,
+  onStatus?: (status: SiteSyncRetryStatus) => void
 ): Promise<T> {
   return retrySiteSyncOperation(
     () => fetchSiteSyncJsonOnce<T>(url, token, {
       ...init,
-      signal: signal
-        ? AbortSignal.any([
-            signal,
-            AbortSignal.timeout(SITE_SYNC_JSON_TIMEOUT_MS)
-          ])
-        : AbortSignal.timeout(SITE_SYNC_JSON_TIMEOUT_MS)
+      signal
     }),
-    signal
+    signal,
+    onStatus
   )
 }
 
@@ -205,15 +416,18 @@ async function uploadObject(
     basename(key)
   )
 
-  await fetchSiteSyncJsonOnce<{ success: boolean }>(
+  const response = await undiciFetch(
     targetUrl(options.targetBaseUrl, '/api/site-sync/object'),
-    token,
     {
       method: 'POST',
       body: form,
-      signal: getJobOperationSignal(jobId, SITE_SYNC_OBJECT_TIMEOUT_MS)
-    }
+      headers: { 'Auth-Token': token },
+      signal: getJobAbortSignal(jobId),
+      dispatcher: agents.upload
+    } as Parameters<typeof undiciFetch>[1]
   )
+  if (!response.ok) throw await responseError(response)
+  await response.json().catch(() => null)
 }
 
 async function downloadSiteSyncObject(
@@ -222,7 +436,7 @@ async function downloadSiteSyncObject(
   token: string,
   key: string
 ): Promise<Buffer> {
-  const response = await fetch(
+  const response = await undiciFetch(
     targetUrl(
       options.targetBaseUrl,
       `/api/site-sync/object?key=${encodeURIComponent(key)}`
@@ -231,7 +445,8 @@ async function downloadSiteSyncObject(
       headers: {
         'Auth-Token': token
       },
-      signal: getJobOperationSignal(jobId, SITE_SYNC_OBJECT_TIMEOUT_MS)
+      signal: getJobAbortSignal(jobId),
+      dispatcher: agents.object
     }
   )
   if (!response.ok) throw await responseError(response)
@@ -287,6 +502,16 @@ async function runSiteSyncPull(
   const progressMessage = (suffix = '') => (
     `扫描 ${scanned}/${totalMedia || scanned} · 新增 ${added} · 跳过 ${skipped} · 失败 ${failedKeys.size}${suffix}`
   )
+  const updateLiveStatus = (step: string, status?: SiteSyncRetryStatus) => {
+    const detail = status ? formatRetryStatus(step, status) : step
+    try {
+      updateBackupJob(jobId, {
+        message: progressMessage(` · ${detail}`)
+      })
+    } catch {
+      // Progress messages must never fail the sync itself.
+    }
+  }
   const failAndCheckpoint = (error: unknown) => {
     const cancelled = isJobCancellationRequested(jobId)
       || isJobCancelledError(error)
@@ -311,7 +536,8 @@ async function runSiteSyncPull(
         targetUrl(options.targetBaseUrl, '/api/site-sync/users'),
         token,
         undefined,
-        jobSignal
+        jobSignal,
+        status => updateLiveStatus('连接目标站点', status)
       )).users
     )
 
@@ -324,15 +550,18 @@ async function runSiteSyncPull(
       targetUrl(options.targetBaseUrl, path),
       token,
       undefined,
-      jobSignal
+      jobSignal,
+      status => updateLiveStatus('读取远程媒体清单', status)
     )
 
     const processBundleOnce = async (
       bundle: SiteSyncMediaBundle,
-      isRetry: boolean
+      isRetry: boolean,
+      setStep: (step: string) => void
     ): Promise<'added' | 'skipped'> => {
       const { media, assets } = bundle
       throwIfJobCancellationRequested(jobId)
+      setStep(`准备同步媒体 ${media.key}`)
       if (media.ownerUsername && !targetUsers.has(media.ownerUsername)) {
         throw new Error(`当前站点缺少同名用户：${media.ownerUsername}`)
       }
@@ -350,6 +579,7 @@ async function runSiteSyncPull(
         : null
       for (const asset of assets) {
         throwIfJobCancellationRequested(jobId)
+        setStep(`下载对象 ${basename(asset.key)}`)
         const existedBefore = Boolean(await backend.head(asset.key))
         if (options.conflictMode === 'skip' && existedBefore) {
           continue
@@ -366,6 +596,7 @@ async function runSiteSyncPull(
             `同步对象大小不一致：${asset.key}，预期 ${asset.size}，实际 ${bytes.length}`
           )
         }
+        setStep(`写入对象 ${basename(asset.key)}`)
         const isPrimary = asset.key === media.key
         recordSiteSyncArtifact({
           jobId,
@@ -393,16 +624,23 @@ async function runSiteSyncPull(
         throwIfJobCancellationRequested(jobId)
       }
 
+      setStep(`写入媒体记录 ${media.key}`)
       await applySiteSyncMedia(media, 'overwrite', actorUserId)
       completeSiteSyncMediaArtifacts(jobId, media.key)
       return 'added'
     }
-    const processBundle = (bundle: SiteSyncMediaBundle, isRetry: boolean) => (
-      retrySiteSyncOperation(
-        () => processBundleOnce(bundle, isRetry),
-        jobSignal
+    const processBundle = (bundle: SiteSyncMediaBundle, isRetry: boolean) => {
+      let step = `同步媒体 ${bundle.media.key}`
+      return retrySiteSyncOperation(
+        () => processBundleOnce(
+          bundle,
+          isRetry,
+          (value) => { step = value }
+        ),
+        jobSignal,
+        status => updateLiveStatus(step, status)
       )
-    )
+    }
     const recordOutcome = (outcome: 'added' | 'skipped', fileCount: number) => {
       if (outcome === 'added') added += 1
       else skipped += 1
@@ -525,7 +763,16 @@ export async function runSiteSyncJob(
       targetUrl(options.targetBaseUrl, '/api/site-sync/inventory'),
       token,
       undefined,
-      jobSignal
+      jobSignal,
+      (status) => {
+        try {
+          updateBackupJob(jobId, {
+            message: formatRetryStatus('连接目标站点', status)
+          })
+        } catch {
+          // Keep the sync running even if a progress update cannot be stored.
+        }
+      }
     )
     const targetUsers = new Set(inventory.users)
     const targetMedia = new Set(inventory.mediaKeys)
@@ -614,6 +861,16 @@ export async function runSiteSyncJob(
         }
       })
     }
+    const updateLiveStatus = (step: string, status?: SiteSyncRetryStatus) => {
+      const detail = status ? formatRetryStatus(step, status) : step
+      try {
+        updateBackupJob(jobId, {
+          message: `扫描 ${scanned}/${rows.length} · 新增 ${added} · 跳过 ${skipped} · 失败 ${failedKeys.size} · ${detail}`
+        })
+      } catch {
+        // Progress messages must never fail the sync itself.
+      }
+    }
 
     plans.sort((a, b) => (
       a.row.key < b.row.key
@@ -624,14 +881,20 @@ export async function runSiteSyncJob(
     ))
     lastMediaKey = lastMediaKey || ''
     let lastCheckpointAt = 0
-    const processPlanOnce = async (plan: typeof plans[number], isRetry: boolean) => {
+    const processPlanOnce = async (
+      plan: typeof plans[number],
+      isRetry: boolean,
+      setStep: (step: string) => void
+    ) => {
       const { row, ownerUsername, backend, keys } = plan
       throwIfJobCancellationRequested(jobId)
+      setStep(`准备同步媒体 ${row.key}`)
       if (
         !isRetry
         && options.conflictMode === 'skip'
         && targetMedia.has(row.key)
       ) {
+        setStep(`提交已存在的媒体 ${row.key}`)
         await fetchSiteSyncJsonOnce<{ success: boolean }>(
           targetUrl(options.targetBaseUrl, '/api/site-sync/complete'),
           token,
@@ -639,7 +902,7 @@ export async function runSiteSyncJob(
             method: 'POST',
             headers: { 'Content-Type': 'application/json' },
             body: JSON.stringify({ jobId, mediaKey: row.key }),
-            signal: getJobOperationSignal(jobId, SITE_SYNC_JSON_TIMEOUT_MS)
+            signal: getJobAbortSignal(jobId)
           }
         )
         skipped += 1
@@ -650,6 +913,7 @@ export async function runSiteSyncJob(
 
       for (const key of keys) {
         throwIfJobCancellationRequested(jobId)
+        setStep(`上传对象 ${basename(key)}`)
         const stored = await backend.head(key)
         if (!stored) throw new Error(`源文件不存在：${key}`)
         if (
@@ -670,6 +934,7 @@ export async function runSiteSyncJob(
       }
 
       throwIfJobCancellationRequested(jobId)
+      setStep(`写入媒体记录 ${row.key}`)
       await fetchSiteSyncJsonOnce<{ success: boolean }>(
         targetUrl(options.targetBaseUrl, '/api/site-sync/media'),
         token,
@@ -681,7 +946,7 @@ export async function runSiteSyncJob(
             media: toSiteSyncMediaTransferWithTags(row, ownerUsername),
             conflictMode: options.conflictMode
           }),
-          signal: getJobOperationSignal(jobId, SITE_SYNC_JSON_TIMEOUT_MS)
+          signal: getJobAbortSignal(jobId)
         }
       )
 
@@ -692,10 +957,18 @@ export async function runSiteSyncJob(
     const processPlan = (
       plan: typeof plans[number],
       isRetry: boolean
-    ) => retrySiteSyncOperation(
-      () => processPlanOnce(plan, isRetry),
-      jobSignal
-    )
+    ) => {
+      let step = `同步媒体 ${plan.row.key}`
+      return retrySiteSyncOperation(
+        () => processPlanOnce(
+          plan,
+          isRetry,
+          (value) => { step = value }
+        ),
+        jobSignal,
+        status => updateLiveStatus(step, status)
+      )
+    }
 
     const retryPlans = plans.filter(plan => failedKeys.has(plan.row.key))
     for (const plan of retryPlans) {
@@ -712,7 +985,9 @@ export async function runSiteSyncJob(
           jobId,
           cancelled
             ? '任务已取消'
-            : '连续 3 次重试失败，已保存断点',
+            : error instanceof Error
+              ? `${error.message} · 已保存断点`
+              : '连续 3 次重试失败，已保存断点',
           message
         )
         return
@@ -735,7 +1010,9 @@ export async function runSiteSyncJob(
           jobId,
           cancelled
             ? '任务已取消'
-            : '连续 3 次重试失败，已保存断点',
+            : error instanceof Error
+              ? `${error.message} · 已保存断点`
+              : '连续 3 次重试失败，已保存断点',
           message
         )
         return