diff --git a/backend/app/agendas/outcome_tags.py b/backend/app/agendas/outcome_tags.py
index bb37855..68926ac 100644
--- a/backend/app/agendas/outcome_tags.py
+++ b/backend/app/agendas/outcome_tags.py
@@ -66,13 +66,13 @@ def parse_action_metadata(
                 due_date_val = date.fromisoformat(token)
             except ValueError:
                 break
-        elif token_lower in ("todo", "open"):
+        elif token_lower in ("todo", "open", "待办", "待开始"):
             status = ActionStatus.open
-        elif token_lower in ("in_progress", "doing", "progress"):
+        elif token_lower in ("in_progress", "doing", "progress", "进行中"):
             status = ActionStatus.in_progress
-        elif token_lower in ("done", "completed", "finish", "finished"):
+        elif token_lower in ("done", "completed", "finish", "finished", "已完成", "完成"):
             status = ActionStatus.done
-        elif token_lower in ("canceled", "cancelled"):
+        elif token_lower in ("canceled", "cancelled", "已取消", "取消"):
             status = ActionStatus.canceled
         else:
             break
diff --git a/backend/tests/domain/test_bidirectional_actions.py b/backend/tests/domain/test_bidirectional_actions.py
index 5cc054b..1a3312e 100644
--- a/backend/tests/domain/test_bidirectional_actions.py
+++ b/backend/tests/domain/test_bidirectional_actions.py
@@ -84,6 +84,40 @@ def test_parse_outcome_tags_extended_syntax():
     assert actions[3].content == "传统无括号待办"
 
 
+def test_parse_outcome_tags_chinese_status_tokens():
+    md = """
+@行动:[待办][@林宇][2026-10-01] 整理压测报告
+@行动:[待开始][@乔安] 准备回滚预案
+@行动:[进行中][@林宇] 推进网关限流改造
+@行动:[已完成][@乔安][2026-09-30] 完成发布清单核验
+@行动:[已取消] 旧版接口迁移计划
+"""
+    tags = parse_outcome_tags(md)
+    assert len(tags) == 5
+
+    assert tags[0].status == ActionStatus.open
+    assert tags[0].owner_name == "林宇"
+    assert tags[0].due_date == date(2026, 10, 1)
+    assert tags[0].content == "整理压测报告"
+
+    assert tags[1].status == ActionStatus.open
+    assert tags[1].owner_name == "乔安"
+    assert tags[1].content == "准备回滚预案"
+
+    assert tags[2].status == ActionStatus.in_progress
+    assert tags[2].owner_name == "林宇"
+    assert tags[2].content == "推进网关限流改造"
+
+    assert tags[3].status == ActionStatus.done
+    assert tags[3].owner_name == "乔安"
+    assert tags[3].due_date == date(2026, 9, 30)
+    assert tags[3].content == "完成发布清单核验"
+
+    assert tags[4].status == ActionStatus.canceled
+    assert tags[4].owner_name is None
+    assert tags[4].content == "旧版接口迁移计划"
+
+
 def test_rewrite_action_in_notes():
     notes = """# Notes
 - List item
diff --git a/docs/assets/demo_meetflow.gif b/docs/assets/demo_meetflow.gif
index 163dd25..7e294af 100644
Binary files a/docs/assets/demo_meetflow.gif and b/docs/assets/demo_meetflow.gif differ
diff --git a/frontend/src/api/client.ts b/frontend/src/api/client.ts
index 1b02524..9c3acec 100644
--- a/frontend/src/api/client.ts
+++ b/frontend/src/api/client.ts
@@ -1,4 +1,5 @@
 import { locale } from '../i18n'
+import { translateBackendError } from '../utils/errors'
 
 export class ApiError extends Error {
   constructor(
@@ -25,7 +26,12 @@ export function apiErrorMessage(
     && 'message' in payload.error
     && typeof payload.error.message === 'string'
   ) {
-    return payload.error.message
+    const code = 'code' in payload.error && typeof payload.error.code === 'string' ? payload.error.code : null
+    const translated = translateBackendError(payload.error.message, code)
+    if (locale.value === 'en' && /[\u4e00-\u9fff]/.test(translated) && !/[\u4e00-\u9fff]/.test(fallback)) {
+      return fallback
+    }
+    return translated
   }
   return fallback
 }
diff --git a/frontend/src/api/plugin-stream.ts b/frontend/src/api/plugin-stream.ts
index 1c279e2..540f8c6 100644
--- a/frontend/src/api/plugin-stream.ts
+++ b/frontend/src/api/plugin-stream.ts
@@ -1,4 +1,5 @@
 import { locale } from '../i18n'
+import { translateBackendError } from '../utils/errors'
 import { apiErrorMessage, dispatchAuthExpired } from './client'
 
 function consumeEvent(block: string, onDelta: (text: string) => void): boolean {
@@ -24,7 +25,8 @@ function consumeEvent(block: string, onDelta: (text: string) => void): boolean {
   }
   if (event === 'error') {
     if (payload && typeof payload === 'object' && 'message' in payload && typeof payload.message === 'string') {
-      throw new Error(payload.message)
+      const code = 'code' in payload && typeof payload.code === 'string' ? payload.code : null
+      throw new Error(translateBackendError(payload.message, code))
     }
     throw new Error(locale.value === 'en' ? 'Failed to generate AI work brief, please try again later' : 'AI 工作简报生成失败，请稍后重试')
   }
diff --git a/frontend/src/components/AgendaDetail.vue b/frontend/src/components/AgendaDetail.vue
index 06c74f7..6e34abb 100644
--- a/frontend/src/components/AgendaDetail.vue
+++ b/frontend/src/components/AgendaDetail.vue
@@ -479,7 +479,7 @@ const noteActionTags = computed(() => {
 <template>
   <div class="agenda-detail" data-testid="agenda-detail">
     <header class="agenda-detail-header">
-      <div><p class="eyebrow">Current topic</p><input v-model="draft.title" class="agenda-title-input" :aria-label="tr('议题标题', 'Agenda Title')" :readonly="!canContribute" /></div>
+      <div><p class="eyebrow">{{ tr('当前议题', 'Current topic') }}</p><input v-model="draft.title" class="agenda-title-input" :aria-label="tr('议题标题', 'Agenda Title')" :readonly="!canContribute" /></div>
       <div class="agenda-detail-status">
         <StatusPill :status="props.item.status" kind="agenda" />
         <n-tag v-if="item.carry_from_open_question_id" size="small" :bordered="false">{{ tr('来自开放问题', 'From Question') }}</n-tag>
@@ -532,7 +532,7 @@ const noteActionTags = computed(() => {
       <n-button v-if="canCopy" quaternary size="small" @click="openCopy">{{ tr('复制到其他会议', 'Copy to Meeting') }}</n-button>
     </div>
 
-    <section class="agenda-outcomes"><header class="section-heading"><div><p class="eyebrow">Outcomes</p><h2>{{ tr('本议题产出', 'Topic Outcomes') }}</h2></div><div v-if="canContribute" class="outcome-action-group" data-testid="outcome-actions"><button class="button button-small button-quiet" @click="composer = 'decision'">{{ tr('+ 决策', '+ Decision') }}</button><button class="button button-small button-quiet" @click="composer = 'action'">{{ tr('+ 行动', '+ Action') }}</button><button class="button button-small button-quiet" @click="composer = 'question'">{{ tr('+ 开放问题', '+ Question') }}</button></div></header>
+    <section class="agenda-outcomes"><header class="section-heading"><div><p class="eyebrow">{{ tr('议题产出', 'Outcomes') }}</p><h2>{{ tr('本议题产出', 'Topic Outcomes') }}</h2></div><div v-if="canContribute" class="outcome-action-group" data-testid="outcome-actions"><button class="button button-small button-quiet" @click="composer = 'decision'">{{ tr('+ 决策', '+ Decision') }}</button><button class="button button-small button-quiet" @click="composer = 'action'">{{ tr('+ 行动', '+ Action') }}</button><button class="button button-small button-quiet" @click="composer = 'question'">{{ tr('+ 开放问题', '+ Question') }}</button></div></header>
       <OutcomeComposer v-if="canContribute && composer" :mode="composer" :meeting="meeting" :item="item" @close="composer = null" @saved="emit('changed')" />
       <div class="outcome-list">
         <article
@@ -603,7 +603,7 @@ const noteActionTags = computed(() => {
     </section>
 
     <section class="agenda-attachments" data-testid="agenda-attachments">
-      <header class="section-heading"><div><p class="eyebrow">Attachments</p><h2>{{ tr('议题附件', 'Attachments') }}</h2></div></header>
+      <header class="section-heading"><div><p class="eyebrow">{{ tr('相关附件', 'Attachments') }}</p><h2>{{ tr('议题附件', 'Attachments') }}</h2></div></header>
       <AttachmentPanel target-type="agenda_item" :target-id="item.id" :attachments="attachments" :can-contribute="canContribute" @uploaded="onAttachmentUploaded" @deleted="onAttachmentDeleted" />
     </section>
 
diff --git a/frontend/src/components/AgendaQueue.vue b/frontend/src/components/AgendaQueue.vue
index a6a1afc..9c64f4a 100644
--- a/frontend/src/components/AgendaQueue.vue
+++ b/frontend/src/components/AgendaQueue.vue
@@ -242,7 +242,7 @@ function onMenuSelect(item: AgendaItem, key: string) {
 
 <template>
   <aside class="agenda-queue" data-testid="agenda-queue">
-    <header class="section-heading"><div><p class="eyebrow">Agenda</p><h2>{{ tr('议题队列', 'Agenda Queue') }}</h2></div><button v-if="canContribute" class="button button-small button-primary" @click="adding = !adding">{{ adding ? tr('收起', 'Close') : tr('+ 议题', '+ Agenda') }}</button></header>
+    <header class="section-heading"><div><p class="eyebrow">{{ tr('议程编排', 'Agenda') }}</p><h2>{{ tr('议题队列', 'Agenda Queue') }}</h2></div><button v-if="canContribute" class="button button-small button-primary" @click="adding = !adding">{{ adding ? tr('收起', 'Close') : tr('+ 议题', '+ Agenda') }}</button></header>
     <form v-if="canContribute && adding" class="agenda-add-form" @submit.prevent="addAgenda">
       <label>{{ tr('议题标题', 'Agenda Title') }}<input v-model="title" required /></label>
       <label>{{ tr('类型', 'Type') }}<select v-model="agendaType"><option value="information">{{ tr('信息同步', 'Info Sync') }}</option><option value="discussion">{{ tr('讨论', 'Discussion') }}</option><option value="decision">{{ tr('决策', 'Decision') }}</option></select></label>
diff --git a/frontend/src/components/AgendaWorkbench.vue b/frontend/src/components/AgendaWorkbench.vue
index faa86a5..317b06b 100644
--- a/frontend/src/components/AgendaWorkbench.vue
+++ b/frontend/src/components/AgendaWorkbench.vue
@@ -69,7 +69,7 @@ defineExpose({ flushCurrentDraft })
     <Transition name="agenda-detail" mode="out-in">
       <AgendaDetail v-if="selected" :key="selected.id" ref="detail" :meeting="meeting" :item="selected" :can-contribute="canContribute" @changed="emit('reload')" @advance="advance" />
       <div v-else class="agenda-empty-compact" data-testid="agenda-detail">
-        <div><p class="eyebrow">Current topic</p><h2>{{ tr('还没有议题', 'No agenda items yet') }}</h2><p>{{ tr('从右侧队列添加本次会议的第一个议题。', 'Add the first agenda item for this meeting from the queue on the right.') }}</p></div>
+        <div><p class="eyebrow">{{ tr('当前议题', 'Current topic') }}</p><h2>{{ tr('还没有议题', 'No agenda items yet') }}</h2><p>{{ tr('从右侧队列添加本次会议的第一个议题。', 'Add the first agenda item for this meeting from the queue on the right.') }}</p></div>
       </div>
     </Transition>
     <AgendaQueue :meeting="meeting" :can-contribute="canContribute" :selected-id="selectedId" :opening-id="openingId" :open-error="openError" @select="openAgenda" @changed="emit('reload')" />
diff --git a/frontend/src/components/CompletedMeetingChain.vue b/frontend/src/components/CompletedMeetingChain.vue
index 26ea729..0f06c16 100644
--- a/frontend/src/components/CompletedMeetingChain.vue
+++ b/frontend/src/components/CompletedMeetingChain.vue
@@ -145,7 +145,7 @@ async function addAmendment() {
   <div class="completed-chain">
     <n-card class="completed-summary">
       <header class="section-heading">
-        <div><p class="eyebrow">Trusted record</p><h2>{{ tr('会议完成链条', 'Completed Meeting Record') }}</h2></div>
+        <div><p class="eyebrow">{{ tr('可信档案', 'Trusted record') }}</p><h2>{{ tr('会议完成链条', 'Completed Meeting Record') }}</h2></div>
         <div v-if="canContribute" class="page-header-actions"><button class="button button-quiet" @click="amendmentOpen = !amendmentOpen">{{ tr('添加更正', 'Add Amendment') }}</button></div>
       </header>
       <p class="snapshot-meta">{{ tr(`快照 #${meeting.current_snapshot?.completion_number ?? '—'} · 原始记录保持只读`, `Snapshot #${meeting.current_snapshot?.completion_number ?? '—'} · Original record is read-only`) }}</p>
diff --git a/frontend/src/components/OutcomeComposer.vue b/frontend/src/components/OutcomeComposer.vue
index 63cdf2d..2316e6a 100644
--- a/frontend/src/components/OutcomeComposer.vue
+++ b/frontend/src/components/OutcomeComposer.vue
@@ -6,6 +6,7 @@ import { api } from '../api/client'
 import type { AgendaItem, Meeting } from '../domain/meetings'
 import type { ActionPriority } from '../domain/outcomes'
 import { useI18n } from '../i18n'
+import { errorMessage } from '../utils/errors'
 import MarkdownEditor from './MarkdownEditor.vue'
 import PluginEditorSlot from './PluginEditorSlot.vue'
 
@@ -46,7 +47,7 @@ async function save() {
     emit('saved')
     emit('close')
   } catch (caught) {
-    error.value = caught instanceof Error ? caught.message : tr(`${labels.value}保存失败`, `Failed to save ${labels.value}`)
+    error.value = errorMessage(caught, tr(`${labels.value}保存失败`, `Failed to save ${labels.value}`))
   } finally {
     saving.value = false
   }
diff --git a/frontend/src/components/ProjectActivityTab.vue b/frontend/src/components/ProjectActivityTab.vue
index 667f800..ede598e 100644
--- a/frontend/src/components/ProjectActivityTab.vue
+++ b/frontend/src/components/ProjectActivityTab.vue
@@ -208,7 +208,7 @@ onMounted(() => {
 
 <template>
   <section class="workspace-section project-activity-tab">
-    <header class="section-heading"><div><p class="eyebrow">Activity</p><h2>{{ tr('项目动态', 'Project Activity') }}</h2></div></header>
+    <header class="section-heading"><div><p class="eyebrow">{{ tr('动态流', 'Activity') }}</p><h2>{{ tr('项目动态', 'Project Activity') }}</h2></div></header>
 
     <ProjectUpdateComposer v-if="canContribute" :project-id="project.id" :health="project.health" @saved="onComposerSaved" />
 
diff --git a/frontend/src/components/ProjectOverview.vue b/frontend/src/components/ProjectOverview.vue
index d522f49..d08eab4 100644
--- a/frontend/src/components/ProjectOverview.vue
+++ b/frontend/src/components/ProjectOverview.vue
@@ -68,7 +68,7 @@ onMounted(async () => {
     <section class="workspace-section project-dashboard-card">
       <div class="section-heading">
         <div>
-          <p class="eyebrow">Project state</p>
+          <p class="eyebrow">{{ tr('状态概览', 'Project state') }}</p>
           <h2>{{ tr('项目状态', 'Project State') }}</h2>
         </div>
       </div>
diff --git a/frontend/src/components/ProjectUpdateComposer.vue b/frontend/src/components/ProjectUpdateComposer.vue
index f795072..7d0b8b1 100644
--- a/frontend/src/components/ProjectUpdateComposer.vue
+++ b/frontend/src/components/ProjectUpdateComposer.vue
@@ -39,7 +39,7 @@ async function submit() {
 <template>
   <form class="project-update-composer" @submit.prevent="submit">
     <div class="composer-heading">
-      <div><p class="eyebrow">Progress update</p><h3>{{ tr('追加项目进展', 'Post Project Update') }}</h3></div>
+      <div><p class="eyebrow">{{ tr('进展更新', 'Progress update') }}</p><h3>{{ tr('追加项目进展', 'Post Project Update') }}</h3></div>
       <label>{{ tr('健康度', 'Health') }}<select v-model="health"><option value="on_track">{{ tr('进展正常', 'On Track') }}</option><option value="at_risk">{{ tr('存在风险', 'At Risk') }}</option><option value="off_track">{{ tr('偏离计划', 'Off Track') }}</option><option value="unset">{{ tr('未设置', 'Unset') }}</option></select></label>
     </div>
     <PluginEditorSlot :editor-label="tr('进展记录', 'Progress Update')" v-model="content" data-testid="project-update-editor" target-type="project" :target-id="projectId" slot="project-update-editor" :metadata="{ projectId }" @notice="error = $event">
diff --git a/frontend/src/composables/useVersionedSave.ts b/frontend/src/composables/useVersionedSave.ts
index fe00020..c0c90a5 100644
--- a/frontend/src/composables/useVersionedSave.ts
+++ b/frontend/src/composables/useVersionedSave.ts
@@ -1,6 +1,7 @@
 import { ref, type Ref } from 'vue'
 
 import { ApiError } from '../api/client'
+import { errorMessage } from '../utils/errors'
 
 /**
  * Shared optimistic-concurrency primitive for entities saved with `expected_version`.
@@ -42,7 +43,7 @@ export function useVersionedSave<T>(
         }
         return null
       }
-      error.value = reason instanceof Error ? reason.message : String(reason)
+      error.value = errorMessage(reason, String(reason))
       return null
     } finally {
       saving.value = false
diff --git a/frontend/src/i18n/index.ts b/frontend/src/i18n/index.ts
index ac3bcd2..0bef2e5 100644
--- a/frontend/src/i18n/index.ts
+++ b/frontend/src/i18n/index.ts
@@ -1,4 +1,4 @@
-import { computed, ref } from 'vue'
+import { computed, ref, watch } from 'vue'
 
 export type Locale = 'zh' | 'en'
 
@@ -16,13 +16,30 @@ function readInitialLocale(): Locale {
   return 'zh'
 }
 
+function syncDocumentLocale(next: Locale): void {
+  try {
+    if (typeof document !== 'undefined' && document.documentElement) {
+      document.documentElement.lang = next
+    }
+    if (typeof window !== 'undefined') {
+      window.dispatchEvent(new CustomEvent('meetflow:lang-change', { detail: { lang: next } }))
+    }
+  } catch {
+    // Ignore DOM/event errors in restricted environments.
+  }
+}
+
 export const locale = ref<Locale>(readInitialLocale())
+syncDocumentLocale(locale.value)
+
+watch(locale, (next) => {
+  syncDocumentLocale(next)
+})
 
 export const isEn = computed(() => locale.value === 'en')
 
 export function setLocale(lang: Locale): void {
   const next: Locale = lang === 'en' ? 'en' : 'zh'
-  locale.value = next
   try {
     if (typeof window !== 'undefined' && window.localStorage) {
       window.localStorage.setItem(STORAGE_KEY, next)
@@ -30,6 +47,8 @@ export function setLocale(lang: Locale): void {
   } catch {
     // Ignore storage write errors.
   }
+  locale.value = next
+  syncDocumentLocale(next)
 }
 
 export function toggleLocale(): Locale {
diff --git a/frontend/src/tests/agenda-workbench.test.ts b/frontend/src/tests/agenda-workbench.test.ts
index c26c054..1b90f32 100644
--- a/frontend/src/tests/agenda-workbench.test.ts
+++ b/frontend/src/tests/agenda-workbench.test.ts
@@ -138,7 +138,7 @@ describe('agenda workbench', () => {
     expect(workbench).toContainElement(detail)
     expect(workbench).toContainElement(queue)
     expect(detail).toHaveClass('agenda-empty-compact')
-    expect(within(detail).getByText('Current topic')).toBeVisible()
+    expect(within(detail).getByText('当前议题')).toBeVisible()
     expect(detail.compareDocumentPosition(queue) & Node.DOCUMENT_POSITION_FOLLOWING).toBeTruthy()
     expect(within(queue).getByRole('button', { name: '+ 议题' })).toBeVisible()
     expect(within(detail).queryByRole('button', { name: '添加议题' })).not.toBeInTheDocument()
diff --git a/frontend/src/tests/ai-work-assistant-plugin.test.ts b/frontend/src/tests/ai-work-assistant-plugin.test.ts
index 3db5991..dbe2155 100644
--- a/frontend/src/tests/ai-work-assistant-plugin.test.ts
+++ b/frontend/src/tests/ai-work-assistant-plugin.test.ts
@@ -161,3 +161,27 @@ it('does not mutate editor content when a job fails', async () => {
   expect(emitted().draft).toBeUndefined()
   expect(emitted().notice).toEqual([['模型不可用']])
 })
+
+it('re-renders mounted assistant controls reactively when language switches between zh and en', async () => {
+  const { setLocale } = await import('../i18n')
+  setLocale('zh')
+  const registered = registerAssistant()
+  renderAssistant(registered, 'meeting-summary-editor')
+
+  expect(screen.getByText('AI 协助纪要')).toBeInTheDocument()
+  expect(screen.getByText('当前编辑块')).toBeInTheDocument()
+  expect(screen.getByRole('button', { name: '生成会议纪要' })).toBeInTheDocument()
+
+  setLocale('en')
+  await nextTick()
+
+  expect(screen.getByText('AI Summary Assistant')).toBeInTheDocument()
+  expect(screen.getByText('Current Block')).toBeInTheDocument()
+  expect(screen.getByRole('button', { name: 'Generate Meeting Minutes' })).toBeInTheDocument()
+
+  setLocale('zh')
+  await nextTick()
+
+  expect(screen.getByText('AI 协助纪要')).toBeInTheDocument()
+  expect(screen.getByRole('button', { name: '生成会议纪要' })).toBeInTheDocument()
+})
diff --git a/frontend/src/tests/api-client.test.ts b/frontend/src/tests/api-client.test.ts
index 43579ee..be87274 100644
--- a/frontend/src/tests/api-client.test.ts
+++ b/frontend/src/tests/api-client.test.ts
@@ -1,9 +1,14 @@
 import { afterEach, describe, expect, it, vi } from 'vitest'
 
-import { api, apiDownload, ApiError } from '../api/client'
+import { api, apiDownload, ApiError, apiErrorMessage } from '../api/client'
+import { setLocale } from '../i18n'
+import { errorMessage, translateBackendError } from '../utils/errors'
 
 describe('api client', () => {
-  afterEach(() => vi.unstubAllGlobals())
+  afterEach(() => {
+    setLocale('zh')
+    vi.unstubAllGlobals()
+  })
 
   it('sends cookies and JSON content type', async () => {
     const fetchMock = vi.fn().mockResolvedValue(new Response(JSON.stringify({ ok: true }), {
@@ -68,4 +73,21 @@ describe('api client', () => {
     expect(result.filename).toBe('meeting notes.md')
     expect(result.blob.size).toBe(5)
   })
+
+  it('translates backend Chinese errors and worker diagnostics in en mode', () => {
+    setLocale('en')
+
+    expect(apiErrorMessage({ error: { code: 'invalid_credentials', message: '用户名或密码错误' } }))
+      .toBe('Incorrect username or password')
+    expect(apiErrorMessage({ error: { code: 'validation_error', message: '请求参数无效' } }))
+      .toBe('Invalid request parameters')
+    expect(apiErrorMessage({ error: { code: 'meeting_locked', message: '已结束的会议不可直接修改' } }))
+      .toBe('Meeting is locked')
+    expect(translateBackendError('认证或权限失败；检查管理员插件设置中的 API Key、服务地址和权限。', 'provider_auth_failed'))
+      .toBe('Authentication or permission failed; check API Key, endpoint URL, and permissions in plugin settings.')
+    expect(translateBackendError('插件清单无效', 'ManifestError'))
+      .toBe('Invalid plugin manifest')
+    expect(errorMessage(new Error('未知后端中文错误'), 'Sign in failed'))
+      .toBe('Sign in failed')
+  })
 })
diff --git a/frontend/src/tests/meeting-workspace.test.ts b/frontend/src/tests/meeting-workspace.test.ts
index 65e949b..09c6e82 100644
--- a/frontend/src/tests/meeting-workspace.test.ts
+++ b/frontend/src/tests/meeting-workspace.test.ts
@@ -112,7 +112,7 @@ describe('meeting workspace', () => {
 
   it('keeps preparation fields on demand instead of above the active agenda', async () => {
     renderWithProviders(MeetingWorkspaceView)
-    await screen.findByText('Current topic')
+    await screen.findByText('当前议题')
     const preparation = screen.getByRole('button', { name: '准备信息' })
     expect(screen.queryByText('会议准备')).not.toBeInTheDocument()
     await fireEvent.click(preparation)
@@ -140,7 +140,7 @@ describe('meeting workspace', () => {
       .mockResolvedValueOnce(projectFixture())
       .mockResolvedValueOnce(saved)
     renderWithProviders(MeetingWorkspaceView)
-    await screen.findByText('Current topic')
+    await screen.findByText('当前议题')
 
     await fireEvent.click(screen.getByRole('button', { name: '准备信息' }))
     await screen.findByText('会议准备')
@@ -181,7 +181,7 @@ describe('meeting workspace', () => {
       .mockResolvedValueOnce(projectFixture())
       .mockResolvedValueOnce(savedPreparation)
     renderWithProviders(MeetingWorkspaceView)
-    await screen.findByText('Current topic')
+    await screen.findByText('当前议题')
 
     await fireEvent.update(screen.getByLabelText('会议纪要'), '尚未保存的新纪要')
     await fireEvent.click(screen.getByRole('button', { name: '准备信息' }))
@@ -199,7 +199,7 @@ describe('meeting workspace', () => {
       .mockResolvedValueOnce(meetingFixture())
       .mockRejectedValueOnce(new Error('项目读取失败'))
     renderWithProviders(MeetingWorkspaceView)
-    await screen.findByText('Current topic')
+    await screen.findByText('当前议题')
 
     await fireEvent.click(screen.getByRole('button', { name: '准备信息' }))
 
@@ -214,7 +214,7 @@ describe('meeting workspace', () => {
       .mockResolvedValueOnce(projectFixture())
       .mockRejectedValueOnce(new ApiError(409, 'meeting_locked', '已结束的会议不可直接修改'))
     renderWithProviders(MeetingWorkspaceView)
-    await screen.findByText('Current topic')
+    await screen.findByText('当前议题')
 
     await fireEvent.click(screen.getByRole('button', { name: '准备信息' }))
     await screen.findByText('会议准备')
@@ -235,7 +235,7 @@ describe('meeting workspace', () => {
   it('keeps a generated meeting summary local until the minutes are explicitly saved', async () => {
     registerEditorAssistant('meeting-summary-editor', SummaryAssistant)
     renderWithProviders(MeetingWorkspaceView)
-    await screen.findByText('Current topic')
+    await screen.findByText('当前议题')
     const summaryEditor = screen.getByTestId('meeting-summary-editor')
     expect(summaryEditor).toContainElement(screen.getByLabelText('会议纪要'))
     expect(within(summaryEditor).getByText('会议纪要')).toBeVisible()
@@ -258,7 +258,7 @@ describe('meeting workspace', () => {
     const summary = '确认灰度发布与回滚边界。'
     editorBuffer.value = summary
     renderWithProviders(MeetingWorkspaceView)
-    await screen.findByText('Current topic')
+    await screen.findByText('当前议题')
 
     await fireEvent.click(screen.getByRole('button', { name: '保存会议纪要' }))
 
@@ -270,7 +270,7 @@ describe('meeting workspace', () => {
 
   it('exposes the meeting raw notes as an accessible editor', async () => {
     renderWithProviders(MeetingWorkspaceView)
-    await screen.findByText('Current topic')
+    await screen.findByText('当前议题')
 
     expect(screen.getByRole('textbox', { name: '整场会议原始笔记' })).toBeInTheDocument()
   })
@@ -280,7 +280,7 @@ describe('meeting workspace', () => {
     apiMock.mockResolvedValue(meetingFixture({ status: 'in_progress', started_at: '2026-07-30T06:38:44.670756' }))
 
     renderWithProviders(MeetingWorkspaceView)
-    await screen.findByText('Current topic')
+    await screen.findByText('当前议题')
 
     expect(screen.getByText('进行 1:15')).toBeVisible()
     now.mockRestore()
@@ -300,7 +300,7 @@ describe('meeting workspace', () => {
       .mockResolvedValueOnce(savedMeeting)
       .mockResolvedValueOnce(started)
     renderWithProviders(MeetingWorkspaceView)
-    await screen.findByText('Current topic')
+    await screen.findByText('当前议题')
 
     await fireEvent.update(screen.getByLabelText('议题标题'), '发布方案已确认')
     await fireEvent.update(screen.getByLabelText('会议纪要'), '迭代评审已确认')
@@ -326,7 +326,7 @@ describe('meeting workspace', () => {
       .mockResolvedValueOnce(projectFixture())
       .mockRejectedValueOnce(new Error('议题保存失败'))
     renderWithProviders(MeetingWorkspaceView)
-    await screen.findByText('Current topic')
+    await screen.findByText('当前议题')
 
     await fireEvent.update(screen.getByLabelText('议题标题'), '无法保存的议题')
     await fireEvent.click(screen.getByRole('button', { name: '开始会议' }))
@@ -342,7 +342,7 @@ describe('meeting workspace', () => {
       .mockResolvedValueOnce(projectFixture())
       .mockRejectedValueOnce(new Error('会议保存失败'))
     renderWithProviders(MeetingWorkspaceView)
-    await screen.findByText('Current topic')
+    await screen.findByText('当前议题')
 
     await fireEvent.update(screen.getByLabelText('会议纪要'), '无法保存的会议')
     await fireEvent.click(screen.getByRole('button', { name: '开始会议' }))
@@ -359,7 +359,7 @@ describe('meeting workspace', () => {
       .mockResolvedValueOnce(projectFixture())
       .mockResolvedValueOnce(started)
     renderWithProviders(MeetingWorkspaceView)
-    await screen.findByText('Current topic')
+    await screen.findByText('当前议题')
 
     await fireEvent.click(screen.getByRole('button', { name: '开始会议' }))
 
@@ -376,7 +376,7 @@ describe('meeting workspace', () => {
       .mockResolvedValueOnce(projectFixture())
       .mockResolvedValueOnce(started)
     renderWithProviders(MeetingWorkspaceView)
-    await screen.findByText('Current topic')
+    await screen.findByText('当前议题')
 
     await fireEvent.click(screen.getByRole('button', { name: '开始会议' }))
 
@@ -408,7 +408,7 @@ describe('meeting workspace', () => {
 
   it('protects dirty meeting drafts from browser unload', async () => {
     renderWithProviders(MeetingWorkspaceView)
-    await screen.findByText('Current topic')
+    await screen.findByText('当前议题')
     await fireEvent.update(screen.getByLabelText('会议纪要'), '未保存纪要')
 
     const event = new Event('beforeunload', { cancelable: true })
diff --git a/frontend/src/utils/errors.ts b/frontend/src/utils/errors.ts
index 0d0f194..07d5d48 100644
--- a/frontend/src/utils/errors.ts
+++ b/frontend/src/utils/errors.ts
@@ -1,3 +1,312 @@
+import { locale } from '../i18n'
+
+const CJK_RE = /[\u4e00-\u9fff]/
+
+export const EN_ERROR_MAP: Record<string, string> = {
+  // Auth & users
+  '用户名或密码错误': 'Incorrect username or password',
+  '请先登录': 'Please sign in first',
+  '需要管理员权限': 'Administrator privileges required',
+  '无权访问': 'Permission denied',
+  '账号尚未启用': 'Account is not active yet',
+  '账号已被归档，请联系管理员恢复': 'Account is archived; please contact an administrator to restore it',
+  '账号正在等待管理员批准': 'Account is awaiting administrator approval',
+  '账号申请未获批准': 'Account registration was not approved',
+  '当前不开放注册': 'Registration is currently closed',
+  '当前密码错误': 'Current password is incorrect',
+  '用户不存在': 'User not found',
+  '用户不存在或已被禁用': 'User not found or disabled',
+  '用户名已存在': 'Username is already taken',
+  '不能禁用当前管理员': 'Cannot disable the current administrator',
+  '不能恢复管理员账号': 'Cannot restore an administrator account',
+  '不能拒绝管理员账号': 'Cannot reject an administrator account',
+  '只能恢复已归档成员': 'Only archived members can be restored',
+  '只能批准待审批成员': 'Only pending members can be approved',
+  '只能拒绝待审批成员': 'Only pending members can be rejected',
+
+  // Generic HTTP & validation
+  '请求参数无效': 'Invalid request parameters',
+  '接口不存在': 'Resource not found',
+  '请求方法不受支持': 'HTTP method not allowed',
+  '请求无法处理': 'Unable to process request',
+  '请求来源不受信任': 'Untrusted request origin',
+  '请求失败，请稍后重试': 'Request failed, please try again later',
+  '记录已被其他操作更新，请刷新后重试': 'Record was updated by another operation; please refresh and try again',
+  '内容已更新': 'Content was updated on the server',
+
+  // Projects
+  '项目不存在': 'Project not found',
+  '项目进展不存在': 'Project update not found',
+  '项目标识已存在': 'Project slug is already taken',
+  '项目成员不存在': 'Project member not found',
+  '无权查看此项目': 'You do not have permission to view this project',
+  '无权修改此项目内容': 'You do not have permission to modify this project',
+  '无权管理此项目': 'You do not have permission to manage this project',
+  '只能修改自己发布的项目进展': 'You can only edit project updates you posted',
+  '只有管理员或项目负责人可以删除项目': 'Only an administrator or project lead can delete the project',
+  '项目下已有会议，不能删除': 'Cannot delete a project that already has meetings',
+  '项目已有附件，不能删除': 'Cannot delete a project that already has attachments',
+  '项目已被其他操作更新，请刷新后重试': 'Project was updated by another operation; please refresh and try again',
+  '项目进展已被其他操作更新，请刷新后重试': 'Project update was modified by another operation; please refresh and try again',
+
+  // Meetings & agendas
+  '会议不存在': 'Meeting not found',
+  '会议系列不存在': 'Meeting series not found',
+  '会议参与人不存在': 'Meeting participant not found',
+  '记录创建者不存在': 'Creator not found',
+  '未指定项目': 'Project is not specified',
+  '无权查看此会议': 'You do not have permission to view this meeting',
+  '无权评论此会议': 'You do not have permission to comment on this meeting',
+  '会议已锁定': 'Meeting is locked',
+  '已结束的会议不可直接修改': 'Meeting is locked',
+  '已完成的会议不可修改': 'Completed meeting cannot be modified',
+  '当前会议状态不可修改议程': 'Agenda cannot be modified in the current meeting status',
+  '目标会议不可修改': 'Target meeting cannot be modified',
+  '会议状态不可执行此操作': 'Operation is not allowed in the current meeting status',
+  '会议尚未开始': 'Meeting has not started yet',
+  '会议结束时间必须晚于开始时间': 'Meeting end time must be later than start time',
+  '只有已完成会议可添加更正': 'Amendments can only be added to completed meetings',
+  '会议已更新，请刷新后重试': 'Meeting was updated; please refresh and try again',
+  '会议系列已更新，请刷新后重试': 'Meeting series was updated; please refresh and try again',
+  '会议议程已更新，请刷新后重试': 'Meeting agenda was updated; please refresh and try again',
+  '议题或会议已更新，请刷新后重试': 'Agenda item or meeting was updated; please refresh and try again',
+  '议题或会议已更新': 'Agenda item or meeting was updated',
+  '议题不存在': 'Agenda item not found',
+  '议题关联用户不存在': 'Agenda user not found',
+  '只有待处理议题可以开始': 'Only planned agenda items can be started',
+  '已结束的议题不能移动': 'Completed agenda items cannot be moved',
+  '议题状态不可再次结束': 'Agenda item is already finished',
+  '排序必须包含当前会议的全部且唯一议题': 'Order must include all unique agenda items of the meeting',
+  '议题只能移动到同一项目的会议': 'Agenda items can only be moved to meetings in the same project',
+  '目标会议必须与原会议不同': 'Target meeting must be different from the source meeting',
+  '目标会议已有该议题副本': 'Target meeting already has a copy of this agenda item',
+  '议题已有产出，不能直接删除': 'Cannot delete an agenda item that already has outcomes',
+  '议题已有评论，不能直接删除': 'Cannot delete an agenda item that already has comments',
+  '议题已有附件，不能直接删除': 'Cannot delete an agenda item that already has attachments',
+  '议题成果标签必须每行填写一项非空内容': 'Each outcome tag must be on its own line with non-empty content',
+
+  // Outcomes (decisions, actions, open questions)
+  '决策不存在': 'Decision not found',
+  '行动项不存在': 'Action item not found',
+  '开放问题不存在': 'Open question not found',
+  '议题备注生成的成果不可直接编辑': 'Outcomes derived from agenda notes cannot be edited directly',
+  '仅提议中的决策可编辑': 'Only proposed decisions can be edited',
+  '仅提议中的决策可定稿': 'Only proposed decisions can be finalized',
+  '仅提议中的决策可撤回': 'Only proposed decisions can be withdrawn',
+  '决策已不再接受评审': 'Decision is no longer open for review',
+  '只有指定评审人可提交评审': 'Only assigned reviewers can submit a review',
+  '仅同项目的最终决策可建立替代关系': 'Supersession is only allowed for finalized decisions in the same project',
+  '新决策已建立替代关系': 'New decision already supersedes another decision',
+  '只能关联同项目的最终决策': 'Can only link to a finalized decision in the same project',
+  '开放问题已排入会议': 'Open question is already scheduled into a meeting',
+  '开放问题当前不可排期': 'Open question cannot be scheduled in its current state',
+  '开放问题只能排入之后的会议': 'Open questions can only be scheduled into future meetings',
+  '开放问题已关闭': 'Open question is already closed',
+  '议题已转为开放问题': 'Agenda item has already been converted to an open question',
+  '只有跳过的议题可转为开放问题': 'Only skipped agenda items can be converted to open questions',
+  '议题已复制到目标会议': 'Agenda item has already been copied to the target meeting',
+  '只有跳过的议题可复制': 'Only skipped agenda items can be copied',
+  '议题只能复制到之后的会议': 'Agenda items can only be copied to future meetings',
+  '源议题没有可迁移产物': 'Source agenda item has no outcomes to migrate',
+  '源议题不存在': 'Source agenda item not found',
+  '源议题或目标议题不存在': 'Source or target agenda item not found',
+  '源议题或目标会议不存在': 'Source agenda item or target meeting not found',
+  '源议题与目标议题不能相同': 'Source and target agenda items must be different',
+  '议题不属于同一项目': 'Agenda items do not belong to the same project',
+  '目标会议不存在': 'Target meeting not found',
+  '目标会议不属于同一项目': 'Target meeting does not belong to the same project',
+  '目标会议与开放问题不属于同一项目': 'Target meeting and open question do not belong to the same project',
+  '来源开放问题不存在': 'Source open question not found',
+  '来源开放问题与当前排期不一致': 'Source open question does not match the current schedule',
+  '会议来源不存在': 'Source meeting not found',
+  '项目或会议来源不存在': 'Source project or meeting not found',
+  '会议来源与项目不匹配': 'Source meeting does not match the project',
+  '议题来源与会议不匹配': 'Source agenda item does not match the meeting',
+  '行动项项目与路径项目不匹配': 'Action item project does not match the URL project',
+  '关联用户不存在或未启用': 'Referenced user does not exist or is not active',
+  '会议成果来源链不完整': 'Meeting outcome provenance chain is incomplete',
+  '复制议题违反数据完整性约束': 'Copying agenda item violated data integrity constraints',
+  '开放问题写入违反数据完整性约束': 'Saving open question violated data integrity constraints',
+
+  // Comments & inbox
+  '评论不存在': 'Comment not found',
+  '评论目标不存在': 'Comment target not found',
+  '不支持此评论目标': 'Unsupported comment target',
+  '评论游标无效': 'Invalid comment cursor',
+  '只能分页读取根评论的回复': 'Replies can only be paginated for root comments',
+  '回复必须属于同一评论目标': 'Reply must belong to the same comment target',
+  '评论只能提及会议参与者': 'Comments can only mention meeting participants',
+  '评论提及用户不存在或未启用': 'Mentioned user does not exist or is not active',
+  '只能编辑自己的评论': 'You can only edit your own comments',
+  '只能删除自己的评论': 'You can only delete your own comments',
+  '只能解决自己的评论': 'You can only resolve your own comments',
+  '只能解决评论主题': 'Only root comment threads can be resolved',
+  '只能重开评论主题': 'Only root comment threads can be reopened',
+  '已删除评论不可编辑': 'Deleted comments cannot be edited',
+  '已删除评论不可解决': 'Deleted comments cannot be resolved',
+  '已删除评论不可重开': 'Deleted comments cannot be reopened',
+  '评论已被其他操作更新，请刷新后重试': 'Comment was updated by another operation; please refresh and try again',
+  '通知不存在': 'Notification not found',
+
+  // Attachments, calendar, webhooks
+  '附件不存在': 'Attachment not found',
+  '附件文件不存在': 'Attachment file is missing',
+  '附件目标不存在': 'Attachment target not found',
+  '只能删除自己上传的附件': 'You can only delete attachments you uploaded',
+  '该附件不支持文本预览': 'Text preview is not supported for this attachment',
+  '单个附件不能超过 20 MB': 'Attachment size cannot exceed 20 MB',
+  '分片上传会话不存在或已过期': 'Chunk upload session does not exist or has expired',
+  '分片数量必须大于 0': 'Chunk count must be greater than 0',
+  '分片索引超出范围': 'Chunk index is out of range',
+  '附件 SHA-256 校验不匹配': 'Attachment SHA-256 checksum mismatch',
+  '附件分片路径无效': 'Invalid attachment chunk path',
+  '附件路径无效': 'Invalid attachment path',
+  '日历订阅令牌无效或已过期': 'Calendar subscription token is invalid or expired',
+  'Webhook 地址必须使用 http:// 或 https:// 协议': 'Webhook URL must use http:// or https://',
+  '禁止将 Webhook 发送至本地或内网地址': 'Sending Webhooks to localhost or private network addresses is forbidden',
+
+  // Plugins & AI worker / stream
+  '插件清单无效': 'Invalid plugin manifest',
+  '插件加载失败': 'Failed to load plugin',
+  '插件不存在': 'Plugin not found',
+  '插件配置无效': 'Invalid plugin configuration',
+  '插件配置不完整': 'Plugin configuration is incomplete',
+  '插件输入无效': 'Invalid plugin input',
+  '插件执行超时': 'Plugin execution timed out',
+  '插件执行失败': 'Plugin execution failed',
+  '插件导出失败': 'Plugin export failed',
+  '插件导出结果无效': 'Invalid plugin export result',
+  '插件返回格式无效': 'Invalid plugin response format',
+  '插件不支持流式输出': 'Plugin does not support streaming output',
+  '插件动作不存在': 'Plugin action not found',
+  '插件流式动作不存在': 'Plugin stream action not found',
+  '插件流式动作目标无效': 'Invalid plugin stream target',
+  '插件目标无效': 'Invalid plugin target',
+  '插件任务目标无效': 'Invalid plugin job target',
+  '会议导出器不存在': 'Meeting exporter not found',
+  '插件事件不存在': 'Plugin event not found',
+  '只有失败事件可以重试': 'Only failed events can be retried',
+  'AI 任务不存在': 'AI task not found',
+  '无权查看此 AI 任务': 'You do not have permission to view this AI task',
+  '无权操作此 AI 任务': 'You do not have permission to operate on this AI task',
+  '当前 AI 任务无法取消': 'This AI task cannot be canceled',
+  '当前 AI 草稿无法丢弃': 'This AI draft cannot be dismissed',
+  '当前 AI 任务无法重新运行': 'This AI task cannot be rerun',
+  '当前 AI 草稿无法应用': 'This AI draft cannot be applied',
+  '任务筛选参数不完整': 'Incomplete task filter parameters',
+  'AI 工作简报生成失败，请稍后重试': 'Failed to generate AI work brief, please try again later',
+  'AI 工作简报请求失败，请稍后重试': 'AI work brief request failed, please try again later',
+  'AI 工作简报返回格式无效': 'Invalid AI work brief response format',
+  'AI 工作简报未返回流式内容': 'AI work brief returned no stream content',
+  '认证或权限失败；检查管理员插件设置中的 API Key、服务地址和权限。':
+    'Authentication or permission failed; check API Key, endpoint URL, and permissions in plugin settings.',
+  'AI 服务额度不足；请充值或更换有可用额度的 API Key。':
+    'Insufficient AI service balance; please top up or replace the API Key.',
+  '找不到 AI 服务或模型；检查服务地址和模型名称。':
+    'AI service or model not found; check endpoint URL and model name.',
+  'AI 服务响应超时；请稍后重试或检查超时设置。':
+    'AI service timed out; please try again later or check timeout settings.',
+  'AI 服务限流或配额已用尽；请稍后重试并检查服务额度。':
+    'AI service rate-limited or quota exhausted; please try again later and check quota.',
+  'AI 服务返回 HTTP 状态错误。':
+    'AI service returned an HTTP status error.',
+  '无法连接 AI 服务；检查服务地址和网络。':
+    'Unable to connect to AI service; check endpoint URL and network.',
+  'AI 插件配置不完整；请联系管理员检查插件设置。':
+    'AI plugin configuration is incomplete; please check plugin settings.',
+  'AI 任务输入不符合插件要求。':
+    'AI task input does not meet plugin requirements.',
+  'AI 服务返回内容与插件格式不兼容。':
+    'AI service response is incompatible with plugin format.',
+  'AI 任务执行失败；请查看技术详情或联系管理员。':
+    'AI task execution failed; check technical details or contact an administrator.',
+  '服务重启，未重复发送 AI 请求':
+    'Server restarted; AI request was not resent',
+  '服务重启，事件重新排队':
+    'Server restarted; event was re-queued',
+}
+
+export const EN_ERROR_CODE_MAP: Record<string, string> = {
+  invalid_credentials: 'Incorrect username or password',
+  invalid_request: 'Invalid request parameters',
+  validation_error: 'Invalid request parameters',
+  forbidden: 'Permission denied',
+  admin_required: 'Administrator privileges required',
+  not_authenticated: 'Please sign in first',
+  active_user_required: 'Account is not active yet',
+  not_found: 'Resource not found',
+  method_not_allowed: 'HTTP method not allowed',
+  http_error: 'Unable to process request',
+  meeting_locked: 'Meeting is locked',
+  meeting_completed: 'Completed meeting cannot be modified',
+  meeting_immutable: 'Meeting cannot be modified in its current state',
+  version_conflict: 'Record was updated by another operation; please refresh and try again',
+  provider_auth_failed:
+    'Authentication or permission failed; check API Key, endpoint URL, and permissions in plugin settings.',
+  provider_insufficient_balance:
+    'Insufficient AI service balance; please top up or replace the API Key.',
+  provider_not_found:
+    'AI service or model not found; check endpoint URL and model name.',
+  provider_timeout:
+    'AI service timed out; please try again later or check timeout settings.',
+  provider_rate_limited:
+    'AI service rate-limited or quota exhausted; please try again later and check quota.',
+  provider_http_error:
+    'AI service returned an HTTP status error.',
+  provider_network_error:
+    'Unable to connect to AI service; check endpoint URL and network.',
+  plugin_not_configured:
+    'AI plugin configuration is incomplete; please check plugin settings.',
+  plugin_input_invalid:
+    'AI task input does not meet plugin requirements.',
+  plugin_output_invalid:
+    'AI service response is incompatible with plugin format.',
+  plugin_failed:
+    'AI task execution failed; check technical details or contact an administrator.',
+  process_restarted:
+    'Server restarted; AI request was not resent',
+  ManifestError: 'Invalid plugin manifest',
+}
+
+export function translateBackendError(msg: string, code?: string | null): string {
+  if (!msg) return msg
+  if (locale.value !== 'en') return msg
+
+  const trimmed = msg.trim()
+  if (EN_ERROR_MAP[trimmed]) {
+    return EN_ERROR_MAP[trimmed]
+  }
+
+  const chunkMatch = trimmed.match(/^分片\s+(\d+)\s+尚未上传$/)
+  if (chunkMatch) {
+    return `Chunk ${chunkMatch[1]} has not been uploaded yet`
+  }
+  const webhookStatusMatch = trimmed.match(/^Webhook返回错误状态码:\s*(.+)$/)
+  if (webhookStatusMatch) {
+    return `Webhook returned error status: ${webhookStatusMatch[1]}`
+  }
+  const webhookErrorMatch = trimmed.match(/^Webhook发送失败:\s*(.+)$/)
+  if (webhookErrorMatch) {
+    return `Webhook delivery failed: ${webhookErrorMatch[1]}`
+  }
+
+  if (code && EN_ERROR_CODE_MAP[code]) {
+    return EN_ERROR_CODE_MAP[code]
+  }
+
+  return msg
+}
+
 export function errorMessage(reason: unknown, fallback: string): string {
-  return reason instanceof Error ? reason.message : fallback
+  if (reason instanceof Error) {
+    const code = 'code' in reason && typeof (reason as { code?: unknown }).code === 'string'
+      ? (reason as { code: string }).code
+      : null
+    const translated = translateBackendError(reason.message, code)
+    if (locale.value === 'en' && CJK_RE.test(translated) && fallback && !CJK_RE.test(fallback)) {
+      return fallback
+    }
+    return translated
+  }
+  return translateBackendError(fallback)
 }
diff --git a/frontend/src/views/AccountView.vue b/frontend/src/views/AccountView.vue
index 7a9fda8..8dc40a0 100644
--- a/frontend/src/views/AccountView.vue
+++ b/frontend/src/views/AccountView.vue
@@ -104,7 +104,7 @@ async function changePassword() {
 <template>
   <main class="page page-narrow account-page">
     <header class="page-heading">
-      <div><p class="eyebrow">Account</p><h1>{{ tr('账号设置', 'Account Settings') }}</h1></div>
+      <div><p class="eyebrow">{{ tr('个人账户', 'Account') }}</p><h1>{{ tr('账号设置', 'Account Settings') }}</h1></div>
     </header>
     <n-card :title="tr('修改密码', 'Change Password')">
       <p class="muted">{{ tr('修改后，其他设备上的旧会话也会立即失效。', 'Updating your password immediately invalidates existing sessions on other devices.') }}</p>
diff --git a/frontend/src/views/ActionsView.vue b/frontend/src/views/ActionsView.vue
index c66ba75..f973b90 100644
--- a/frontend/src/views/ActionsView.vue
+++ b/frontend/src/views/ActionsView.vue
@@ -268,7 +268,7 @@ onBeforeUnmount(() => {
 <template>
   <main class="workspace-page">
     <header class="workspace-page-heading">
-      <div><p class="eyebrow">Action hub</p><h1>{{ tr('行动项', 'Actions') }}</h1><p>{{ tr('会议产生的行动在这里汇总、筛选并持续跟踪。', 'Track, filter, and follow up on action items across all meetings.') }}</p></div>
+      <div><p class="eyebrow">{{ tr('行动中心', 'Action hub') }}</p><h1>{{ tr('行动项', 'Actions') }}</h1><p>{{ tr('会议产生的行动在这里汇总、筛选并持续跟踪。', 'Track, filter, and follow up on action items across all meetings.') }}</p></div>
       <span class="metric"><strong>{{ total }}</strong>{{ tr('项', ' items') }}</span>
     </header>
     <section class="workspace-section filter-panel">
diff --git a/frontend/src/views/AdminPluginsView.vue b/frontend/src/views/AdminPluginsView.vue
index 6cb80a6..eeefbb7 100644
--- a/frontend/src/views/AdminPluginsView.vue
+++ b/frontend/src/views/AdminPluginsView.vue
@@ -22,7 +22,7 @@ import { computed, h, onMounted, reactive, ref } from 'vue'
 import { api } from '../api/client'
 import StatusPill from '../components/StatusPill.vue'
 import { useI18n } from '../i18n'
-import { errorMessage } from '../utils/errors'
+import { errorMessage, translateBackendError } from '../utils/errors'
 
 const { tr } = useI18n()
 
@@ -175,6 +175,15 @@ function secretConfigured(plugin: PluginInfo, key: string) {
   return !!value && typeof value === 'object' && 'configured' in value && (value as { configured: boolean }).configured
 }
 
+function fieldLabel(field: ConfigField): string {
+  if (field.label) return field.label
+  if (field.key === 'base_url') return tr('服务地址 (Base URL)', 'Base URL')
+  if (field.key === 'model') return tr('模型名称 (Model)', 'Model')
+  if (field.key === 'timeout_seconds') return tr('超时时间 (秒)', 'Timeout (s)')
+  if (field.key === 'api_key') return tr('API 密钥 (API Key)', 'API Key')
+  return field.key
+}
+
 function pluginDisplayName(plugin: PluginInfo): string {
   if (plugin.id === 'ai-work-assistant' && plugin.name === 'AI 工作助手') {
     return tr('AI 工作助手', 'AI Work Assistant')
@@ -194,7 +203,7 @@ function pluginDisplayDescription(plugin: PluginInfo): string {
   }
   if (plugin.id === 'meeting-export' && plugin.description?.includes('会议上下文导出')) {
     return tr(
-      plugin.description,
+      '将会议上下文导出为结构化 Markdown 或 JSON',
       'Export bounded meeting context as Markdown or JSON',
     )
   }
@@ -206,7 +215,7 @@ const eventColumns = computed<DataTableColumns<PluginEvent>>(() => {
   return [
     { title: tr('事件类型', 'Event Type'), key: 'event_type', minWidth: 200 },
     { title: tr('尝试次数', 'Attempts'), key: 'attempts', minWidth: 100 },
-    { title: tr('最后错误', 'Last Error'), key: 'last_error', minWidth: 220, render: (event) => event.last_error || '—' },
+    { title: tr('最后错误', 'Last Error'), key: 'last_error', minWidth: 220, render: (event) => event.last_error ? translateBackendError(event.last_error) : '—' },
     {
       title: tr('操作', 'Actions'),
       key: 'actions',
@@ -226,7 +235,7 @@ onMounted(() => { void load() })
 
 <template>
   <main class="page">
-    <header class="page-heading"><div><p class="eyebrow">Extensions</p><h1>{{ tr('插件管理', 'Plugin Management') }}</h1><p>{{ tr('配置由服务器管理员安装的可信扩展。代码变更与启停需要重启。', 'Configure trusted extensions installed by the server administrator. Code or state changes require a restart.') }}</p></div><span class="metric"><strong>{{ plugins.length }}</strong> {{ tr('已发现', 'Discovered') }}</span></header>
+    <header class="page-heading"><div><p class="eyebrow">{{ tr('扩展插件', 'Extensions') }}</p><h1>{{ tr('插件管理', 'Plugin Management') }}</h1><p>{{ tr('配置由服务器管理员安装的可信扩展。代码变更与启停需要重启。', 'Configure trusted extensions installed by the server administrator. Code or state changes require a restart.') }}</p></div><span class="metric"><strong>{{ plugins.length }}</strong> {{ tr('已发现', 'Discovered') }}</span></header>
     <n-alert v-if="error" type="error">{{ error }}</n-alert>
     <n-alert v-if="restartRequired" type="warning" class="restart-notice">{{ tr('插件启用状态已保存，重启后生效。', 'Plugin enabled state saved; restart required to take effect.') }}</n-alert>
     <n-grid v-if="plugins.length" class="plugin-grid" :cols="2" :x-gap="16" :y-gap="16">
@@ -246,7 +255,7 @@ onMounted(() => { void load() })
               @update:value="(value: boolean) => toggle(plugin, value)"
             />
           </div>
-          <p v-if="plugin.load_error" class="notice notice-error">{{ plugin.load_error }}</p>
+          <p v-if="plugin.load_error" class="notice notice-error">{{ translateBackendError(plugin.load_error) }}</p>
           <div v-if="plugin.capabilities" class="plugin-capabilities" :aria-label="tr('插件能力', 'Plugin capabilities')">
             <n-tag size="small" :bordered="false">API v{{ plugin.api_version ?? 1 }}</n-tag>
             <n-tag v-if="plugin.loaded" size="small" :bordered="false">{{ tr('已加载', 'Loaded') }}</n-tag>
@@ -256,34 +265,34 @@ onMounted(() => { void load() })
           </div>
           <p class="restart-note">{{ tr('状态变更：', 'State change: ') }}<span>{{ tr('重启后生效', 'Requires restart') }}</span></p>
           <n-form v-if="plugin.config_schema" class="plugin-config" label-placement="top" :show-require-mark="false" @submit.prevent>
-            <n-form-item v-for="field in plugin.config_schema.fields ?? []" :key="field.key" :label="field.label || field.key">
+            <n-form-item v-for="field in plugin.config_schema.fields ?? []" :key="field.key" :label="fieldLabel(field)">
               <n-switch
                 v-if="field.type === 'boolean'"
                 :value="Boolean(draftValue(plugin, field.key))"
-                :aria-label="field.label || field.key"
+                :aria-label="fieldLabel(field)"
                 @update:value="(value: boolean) => setDraft(plugin, field.key, value)"
               />
               <n-input-number
                 v-else-if="field.type === 'number'"
                 :value="numberDraft(plugin, field.key)"
-                :input-props="{ 'aria-label': field.label || field.key, required: field.required }"
+                :input-props="{ 'aria-label': fieldLabel(field), required: field.required }"
                 @update:value="(value: number | null) => setDraft(plugin, field.key, value)"
               />
               <n-input
                 v-else
                 :value="stringDraft(plugin, field.key)"
-                :input-props="{ 'aria-label': field.label || field.key, required: field.required }"
+                :input-props="{ 'aria-label': fieldLabel(field), required: field.required }"
                 @update:value="(value: string) => setDraft(plugin, field.key, value)"
               />
               <template #feedback><span v-if="field.description">{{ field.description }}</span></template>
             </n-form-item>
-            <n-form-item v-for="field in plugin.config_schema.secrets ?? []" :key="field.key" :label="field.label || field.key">
+            <n-form-item v-for="field in plugin.config_schema.secrets ?? []" :key="field.key" :label="fieldLabel(field)">
               <n-input
                 type="password"
                 show-password-on="click"
                 autocomplete="new-password"
                 :value="stringDraft(plugin, field.key)"
-                :input-props="{ 'aria-label': field.label || field.key, autocomplete: 'new-password' }"
+                :input-props="{ 'aria-label': fieldLabel(field), autocomplete: 'new-password' }"
                 :placeholder="secretConfigured(plugin, field.key) ? tr('留空则保持不变', 'Leave blank to keep unchanged') : tr('尚未配置', 'Not configured')"
                 @update:value="(value: string) => setDraft(plugin, field.key, value)"
               />
@@ -292,7 +301,7 @@ onMounted(() => { void load() })
                   <StatusPill status="active" :label="tr('已配置', 'Configured')" />
                   <n-popconfirm :positive-text="tr('确认清除', 'Clear')" :negative-text="tr('取消', 'Cancel')" @positive-click="clearSecret(plugin, field.key)">
                     <template #trigger>
-                      <n-button size="small" type="error" quaternary :aria-label="tr(`清除 ${field.label || field.key}`, `Clear ${field.label || field.key}`)">{{ tr('清除', 'Clear') }}</n-button>
+                      <n-button size="small" type="error" quaternary :aria-label="tr(`清除 ${fieldLabel(field)}`, `Clear ${fieldLabel(field)}`)">{{ tr('清除', 'Clear') }}</n-button>
                     </template>
                     {{ tr('确定清除已保存的敏感配置吗？', 'Clear saved secret configuration?') }}
                   </n-popconfirm>
@@ -304,7 +313,7 @@ onMounted(() => { void load() })
         </n-card>
       </n-grid-item>
     </n-grid>
-    <div v-if="unmatchedErrors.length" class="plugin-errors"><p v-for="item in unmatchedErrors" :key="`${item.plugin_id}-${item.error_type}`" class="notice notice-error">{{ item.plugin_id }} · {{ item.message }}</p></div>
+    <div v-if="unmatchedErrors.length" class="plugin-errors"><p v-for="item in unmatchedErrors" :key="`${item.plugin_id}-${item.error_type}`" class="notice notice-error">{{ item.plugin_id }} · {{ translateBackendError(item.message, item.error_type) }}</p></div>
     <section v-if="failedEvents.length" class="plugin-errors" aria-labelledby="plugin-event-errors-title">
       <h2 id="plugin-event-errors-title">{{ tr('事件失败', 'Failed Events') }}</h2>
       <n-data-table :columns="eventColumns" :data="failedEvents" :bordered="false" size="small" :scroll-x="720" />
diff --git a/frontend/src/views/AdminUsersView.vue b/frontend/src/views/AdminUsersView.vue
index da803d6..59d4ce0 100644
--- a/frontend/src/views/AdminUsersView.vue
+++ b/frontend/src/views/AdminUsersView.vue
@@ -268,13 +268,13 @@ onMounted(load)
 <template>
   <main class="page">
     <header class="page-heading">
-      <div><p class="eyebrow">Administration</p><h1>{{ tr('用户管理', 'User Management') }}</h1><p>{{ tr('审批申请并管理共享工作区成员。', 'Approve requests and manage workspace members.') }}</p></div>
+      <div><p class="eyebrow">{{ tr('系统管理', 'Administration') }}</p><h1>{{ tr('用户管理', 'User Management') }}</h1><p>{{ tr('审批申请并管理共享工作区成员。', 'Approve requests and manage workspace members.') }}</p></div>
       <span class="metric"><strong>{{ pendingCount }}</strong> {{ tr('待审批', 'Pending') }}</span>
     </header>
     <n-alert v-if="error" type="error">{{ error }}</n-alert>
     <section class="panel split-panel">
       <div>
-        <p class="eyebrow">Fixed account</p><h2>{{ tr('创建固定账号', 'Create Fixed Account') }}</h2>
+        <p class="eyebrow">{{ tr('内部开通', 'Fixed account') }}</p><h2>{{ tr('创建固定账号', 'Create Fixed Account') }}</h2>
         <p class="muted">{{ tr('账号创建后立即启用，适合作为演示或内部成员账号。', 'Accounts are enabled immediately upon creation.') }}</p>
       </div>
       <form class="compact-form" @submit.prevent="createFixedAccount">
diff --git a/frontend/src/views/AiTasksView.vue b/frontend/src/views/AiTasksView.vue
index 2777cf6..bd8db76 100644
--- a/frontend/src/views/AiTasksView.vue
+++ b/frontend/src/views/AiTasksView.vue
@@ -10,7 +10,7 @@ import StatusPill from '../components/StatusPill.vue'
 import { loadUserNames, nameOf } from '../composables/useUserNameMap'
 import type { PluginJob } from '../domain/plugin-jobs'
 import { useI18n } from '../i18n'
-import { errorMessage } from '../utils/errors'
+import { errorMessage, translateBackendError } from '../utils/errors'
 import { formatDateTime } from '../utils/time'
 
 const TERMINAL_STATUSES = ['succeeded', 'failed', 'interrupted', 'canceled']
@@ -126,7 +126,7 @@ onUnmounted(() => { if (poller) clearInterval(poller) })
 
 <template>
   <main class="workspace-page ai-tasks-page">
-    <PageHeader eyebrow="AI work" :title="tr('AI 任务', 'AI Tasks')" :summary="tr('这里保留运行状态、结果与失败恢复；生成内容会直接写入发起时的编辑器。', 'Track AI execution status, results, and recovery; generated content is applied directly to the originating editor.')" />
+    <PageHeader :eyebrow="tr('AI 协作', 'AI work')" :title="tr('AI 任务', 'AI Tasks')" :summary="tr('这里保留运行状态、结果与失败恢复；生成内容会直接写入发起时的编辑器。', 'Track AI execution status, results, and recovery; generated content is applied directly to the originating editor.')" />
     <section class="workspace-section ai-task-filters">
       <span>{{ tr('显示范围', 'Scope') }}</span>
       <n-radio-group v-model:value="includeHistory" size="small" :aria-label="tr('显示范围', 'Scope')">
@@ -152,7 +152,7 @@ onUnmounted(() => { if (poller) clearInterval(poller) })
         </header>
         <p v-if="canApplyHint(job)" class="ai-task-apply-hint">{{ tr('在发起页面应用此结果', 'Apply this result on the originating page') }}</p>
         <div v-if="job.error_message" class="ai-task-error">
-          <p>{{ job.error_message }}</p>
+          <p>{{ translateBackendError(job.error_message, job.error_code) }}</p>
         </div>
         <ul class="ai-task-meta">
           <li v-if="job.rerun_of_id">{{ tr(`重跑自任务 #${job.rerun_of_id}`, `Rerun of task #${job.rerun_of_id}`) }}</li>
diff --git a/frontend/src/views/DecisionsView.vue b/frontend/src/views/DecisionsView.vue
index 92a78e5..00244ee 100644
--- a/frontend/src/views/DecisionsView.vue
+++ b/frontend/src/views/DecisionsView.vue
@@ -194,7 +194,7 @@ onBeforeUnmount(() => {
 <template>
   <main class="workspace-page">
     <header class="workspace-page-heading">
-      <div><p class="eyebrow">Decision log</p><h1>{{ tr('决策日志', 'Decisions') }}</h1><p>{{ tr('跨项目查看提案、最终决策及其评审状态。', 'Browse proposals, final decisions, and review status across projects.') }}</p></div>
+      <div><p class="eyebrow">{{ tr('决策台账', 'Decision log') }}</p><h1>{{ tr('决策日志', 'Decisions') }}</h1><p>{{ tr('跨项目查看提案、最终决策及其评审状态。', 'Browse proposals, final decisions, and review status across projects.') }}</p></div>
       <span class="metric"><strong>{{ total }}</strong>{{ tr('项', ' items') }}</span>
     </header>
     <section class="workspace-section filter-panel">
diff --git a/frontend/src/views/HomeView.vue b/frontend/src/views/HomeView.vue
index f40e443..e6dad70 100644
--- a/frontend/src/views/HomeView.vue
+++ b/frontend/src/views/HomeView.vue
@@ -139,7 +139,7 @@ onBeforeUnmount(cancelWorkBrief)
 <template>
   <main class="workspace-page">
     <header class="workspace-page-heading">
-      <div><p class="eyebrow">For you</p><h1>{{ tr('今天需要你关注的事', 'What Needs Your Attention Today') }}</h1><p>{{ tr('把跨项目的待办、评审和会议准备收拢到一个队列。', 'Bring cross-project action items, reviews, and meeting prep into one queue.') }}</p></div>
+      <div><p class="eyebrow">{{ tr('为你推荐', 'For you') }}</p><h1>{{ tr('今天需要你关注的事', 'What Needs Your Attention Today') }}</h1><p>{{ tr('把跨项目的待办、评审和会议准备收拢到一个队列。', 'Bring cross-project action items, reviews, and meeting prep into one queue.') }}</p></div>
       <div class="home-heading-actions">
         <span v-if="response" class="unread-summary">
           <n-badge :value="response.unread_count" :show="response.unread_count > 0" />
@@ -162,7 +162,7 @@ onBeforeUnmount(cancelWorkBrief)
           content-class="home-card-body"
           content-style="padding: 0"
         >
-          <div class="section-heading"><div><p class="eyebrow">Priority queue</p><h2 id="priority-queue-title">{{ tr('需要关注', 'Attention Queue') }}</h2></div><span class="metric"><strong>{{ priorities.length }}</strong> {{ tr('项', 'items') }}</span></div>
+          <div class="section-heading"><div><p class="eyebrow">{{ tr('优先队列', 'Priority queue') }}</p><h2 id="priority-queue-title">{{ tr('需要关注', 'Attention Queue') }}</h2></div><span class="metric"><strong>{{ priorities.length }}</strong> {{ tr('项', 'items') }}</span></div>
           <div v-if="priorities.length" class="attention-list"><AttentionCard v-for="item in priorities" :key="`${item.subject_type}:${item.subject_id}`" :item="item" /></div>
           <n-empty v-else class="empty-state compact" :description="tr('目前没有需要立即处理的事项', 'No items require immediate attention')">
             <p>{{ tr('新的指派、评审和回复会出现在这里。', 'New assignments, reviews, and replies will appear here.') }}</p>
@@ -175,7 +175,7 @@ onBeforeUnmount(cancelWorkBrief)
           content-class="home-card-body"
           content-style="padding: 0"
         >
-          <div class="section-heading"><div><p class="eyebrow">Next up</p><h2 id="upcoming-meetings-title">{{ tr('近期会议', 'Upcoming Meetings') }}</h2></div><RouterLink class="text-link" to="/meetings">{{ tr('全部', 'All') }}</RouterLink></div>
+          <div class="section-heading"><div><p class="eyebrow">{{ tr('即将开始', 'Next up') }}</p><h2 id="upcoming-meetings-title">{{ tr('近期会议', 'Upcoming Meetings') }}</h2></div><RouterLink class="text-link" to="/meetings">{{ tr('全部', 'All') }}</RouterLink></div>
           <RouterLink v-for="item in meetings" :key="item.subject_id" class="upcoming-meeting" :to="`/meetings/${item.subject_id}`"><strong>{{ item.title }}</strong><span>{{ item.project.name }}</span><time v-if="item.scheduled_start">{{ formatDateTime(item.scheduled_start) }}</time></RouterLink>
           <n-empty v-if="!meetings.length" class="empty-state compact" :description="tr('未来七天没有需要你参加的会议。', 'No meetings scheduled for you in the next 7 days.')" />
         </n-card>
@@ -184,7 +184,7 @@ onBeforeUnmount(cancelWorkBrief)
       <n-card tag="section" class="workspace-section ai-work-brief-panel" content-class="home-card-body" content-style="padding: 0">
         <div class="ai-work-brief-heading">
           <div>
-            <p class="eyebrow">Work brief</p>
+            <p class="eyebrow">{{ tr('工作简报', 'Work brief') }}</p>
             <h2>{{ tr('AI 工作简报', 'AI Work Brief') }}</h2>
             <p>{{ workBriefEnabled ? tr('汇总你全部项目中的当前工作，仅供阅读。', 'Summarizes your current work across all projects for quick reading.') : tr('加载工作简报插件后，可汇总你的跨项目工作。', 'Enable the work brief plugin to summarize cross-project work.') }}</p>
             <span v-if="workBrief?.generated_at" class="brief-generated-at">{{ tr('上次生成于', 'Last generated') }} {{ formatDateTime(workBrief.generated_at) }}</span>
diff --git a/frontend/src/views/InboxView.vue b/frontend/src/views/InboxView.vue
index 882970c..5ee4805 100644
--- a/frontend/src/views/InboxView.vue
+++ b/frontend/src/views/InboxView.vue
@@ -170,7 +170,7 @@ onBeforeUnmount(() => {
 <template>
   <main class="workspace-page">
     <header class="workspace-page-heading">
-      <div><p class="eyebrow">Inbox</p><h1>{{ tr('收件箱', 'Inbox') }}</h1><p>{{ tr('评论提及、指派和评审请求都会汇总到这里。', 'Mentions, assignments, and review requests are collected here.') }}</p></div>
+      <div><p class="eyebrow">{{ tr('通知中心', 'Inbox') }}</p><h1>{{ tr('收件箱', 'Inbox') }}</h1><p>{{ tr('评论提及、指派和评审请求都会汇总到这里。', 'Mentions, assignments, and review requests are collected here.') }}</p></div>
       <n-button secondary :disabled="!unreadCount" :loading="readAllBusy" @click="readAll">{{ tr('全部已读', 'Mark All Read') }}</n-button>
     </header>
     <n-alert v-if="error" type="error" class="workspace-section">{{ error }}</n-alert>
diff --git a/frontend/src/views/LoginView.vue b/frontend/src/views/LoginView.vue
index f4cb25c..1e3b999 100644
--- a/frontend/src/views/LoginView.vue
+++ b/frontend/src/views/LoginView.vue
@@ -55,7 +55,7 @@ async function submit() {
 <template>
   <main class="auth-layout">
     <section class="auth-intro">
-      <p class="eyebrow">Shared meeting archive</p>
+      <p class="eyebrow">{{ tr('共享会议档案', 'Shared meeting archive') }}</p>
       <h1 v-if="tr('zh', 'en') === 'zh'">让每次讨论<br />都有清晰的去向。</h1>
       <h1 v-else>Turn every discussion<br />into clear next steps.</h1>
       <p>{{ tr('集中整理会议记录、关键结论、行动项与会后进展。', 'Organize meeting notes, key decisions, action items, and follow-up progress in one place.') }}</p>
diff --git a/frontend/src/views/MeetingWorkspaceView.vue b/frontend/src/views/MeetingWorkspaceView.vue
index 5ac5f5d..c2b033d 100644
--- a/frontend/src/views/MeetingWorkspaceView.vue
+++ b/frontend/src/views/MeetingWorkspaceView.vue
@@ -200,7 +200,7 @@ async function savePreparation() {
     acceptPreparation(saved)
     preparationOpen.value = false
   } catch (caught) {
-    if (caught instanceof ApiError && caught.code === 'meeting_locked') message.error(caught.message)
+    if (caught instanceof ApiError && caught.code === 'meeting_locked') message.error(errorMessage(caught, tr('已结束的会议不可直接修改', 'Meeting is locked')))
     else preparationError.value = errorMessage(caught, tr('准备信息保存失败', 'Failed to save preparation info'))
   } finally {
     preparationSaving.value = false
@@ -411,7 +411,7 @@ onBeforeUnmount(() => {
 
         <section class="workspace-section meeting-summary-section">
           <header class="section-heading">
-            <div><p class="eyebrow">Summary</p><h2>{{ tr('会议纪要', 'Meeting Summary') }}</h2></div>
+            <div><p class="eyebrow">{{ tr('纪要沉淀', 'Summary') }}</p><h2>{{ tr('会议纪要', 'Meeting Summary') }}</h2></div>
             <div class="row-actions">
               <span v-if="minutesSaved || saveState === 'saved'" class="muted" role="status">{{ tr('纪要已保存', 'Summary saved') }}</span>
               <button v-if="canContribute" class="button button-quiet" :disabled="busy || !dirty" @click="saveMinutes">{{ tr('保存会议纪要', 'Save Summary') }}</button>
@@ -426,13 +426,13 @@ onBeforeUnmount(() => {
         </section>
 
         <section class="workspace-section meeting-raw-notes">
-          <header class="section-heading"><div><p class="eyebrow">Notes</p><h2>{{ tr('整场会议原始笔记', 'Raw Meeting Notes') }}</h2></div><SaveStateIndicator role="note" :state="saveState" /></header>
+          <header class="section-heading"><div><p class="eyebrow">{{ tr('会议笔记', 'Notes') }}</p><h2>{{ tr('整场会议原始笔记', 'Raw Meeting Notes') }}</h2></div><SaveStateIndicator role="note" :state="saveState" /></header>
           <MarkdownEditor ref="rawNotesEditor" v-model="draft.raw_notes_markdown" :label="tr('整场会议原始笔记', 'Raw Meeting Notes')" :placeholder="tr('记录整场会议的原始讨论内容…', 'Capture raw discussion notes for the entire meeting…')" :disabled="busy || !canContribute" />
           <p v-if="conflict" class="notice notice-error" role="alert">{{ tr('保存版本已变化，请刷新会议后重新确认本地笔记。', 'Version changed on server. Please refresh and verify local notes.') }}</p>
         </section>
 
         <div class="meeting-tools workspace-section">
-          <div><p class="eyebrow">Meeting tools</p><h2>{{ tr('材料与协作', 'Materials & Collab') }}</h2><p class="muted">{{ tr('材料、评论都可以在会议进行中持续添加，不会离开当前议题。', 'Add materials and comments anytime during the meeting without leaving the active topic.') }}</p></div>
+          <div><p class="eyebrow">{{ tr('会议工具', 'Meeting tools') }}</p><h2>{{ tr('材料与协作', 'Materials & Collab') }}</h2><p class="muted">{{ tr('材料、评论都可以在会议进行中持续添加，不会离开当前议题。', 'Add materials and comments anytime during the meeting without leaving the active topic.') }}</p></div>
           <div class="row-actions">
             <PluginSlot v-if="canContribute" slot="meeting.toolbar.action" target-type="meeting" :target-id="meeting.id" :metadata="{ projectId: meeting.project.id }" />
             <button class="button button-quiet" @click="materialsOpen = true">{{ tr('材料', 'Materials') }} ({{ materialItems.length }})</button>
@@ -443,7 +443,7 @@ onBeforeUnmount(() => {
         <n-drawer :show="preparationOpen" placement="right" :width="'min(560px, 100vw)'" :mask-closable="!preparationSaving" @update:show="(value: boolean) => { if (!value) preparationOpen = false }">
           <n-drawer-content :title="tr('准备信息', 'Prep Info')" closable>
             <section class="meeting-preparation">
-              <header class="section-heading"><div><p class="eyebrow">Preparation</p><h2>{{ tr('会议准备', 'Meeting Prep') }}</h2></div></header>
+              <header class="section-heading"><div><p class="eyebrow">{{ tr('会前准备', 'Preparation') }}</p><h2>{{ tr('会议准备', 'Meeting Prep') }}</h2></div></header>
               <n-form ref="preparationFormRef" :model="preparationForm" :rules="preparationRules" label-placement="top" :show-require-mark="false">
                 <n-form-item :label="tr('会议标题', 'Meeting Title')" path="title">
                   <n-input v-model:value="preparationForm.title" :input-props="{ 'aria-label': tr('会议标题', 'Meeting Title') }" :placeholder="tr('会议标题', 'Meeting Title')" />
diff --git a/frontend/src/views/MeetingsView.vue b/frontend/src/views/MeetingsView.vue
index 3031fad..d708e0b 100644
--- a/frontend/src/views/MeetingsView.vue
+++ b/frontend/src/views/MeetingsView.vue
@@ -146,7 +146,7 @@ onMounted(load)
 <template>
   <main class="workspace-page">
     <header class="workspace-page-heading">
-      <div><p class="eyebrow">Meeting workspace</p><h1>{{ tr('会议', 'Meetings') }}</h1><p>{{ tr('围绕项目组织准备、现场议题、产出和会后档案。', 'Organize prep, live agenda items, outcomes, and archives around projects.') }}</p></div>
+      <div><p class="eyebrow">{{ tr('会议工作区', 'Meeting workspace') }}</p><h1>{{ tr('会议', 'Meetings') }}</h1><p>{{ tr('围绕项目组织准备、现场议题、产出和会后档案。', 'Organize prep, live agenda items, outcomes, and archives around projects.') }}</p></div>
       <button class="button button-primary" @click="createOpen = true">{{ tr('新建会议', 'New Meeting') }}</button>
     </header>
     <MeetingCreateDrawer
diff --git a/frontend/src/views/ProjectDetailView.vue b/frontend/src/views/ProjectDetailView.vue
index cb7c95d..2131972 100644
--- a/frontend/src/views/ProjectDetailView.vue
+++ b/frontend/src/views/ProjectDetailView.vue
@@ -342,7 +342,7 @@ onMounted(load)
     <p v-if="loading" class="empty-state">{{ tr('正在加载项目工作区…', 'Loading project workspace…') }}</p>
     <p v-else-if="error && !project" class="notice notice-error">{{ error }}</p>
     <template v-else-if="project">
-      <PageHeader eyebrow="Project workspace" :title="project.name" :summary="project.summary">
+      <PageHeader :eyebrow="tr('项目工作区', 'Project workspace')" :title="project.name" :summary="project.summary">
         <template #meta>
           <div class="project-context">
             <StatusPill :status="project.status" kind="project" />
diff --git a/frontend/src/views/ProjectsView.vue b/frontend/src/views/ProjectsView.vue
index d08389d..7aaa650 100644
--- a/frontend/src/views/ProjectsView.vue
+++ b/frontend/src/views/ProjectsView.vue
@@ -95,7 +95,7 @@ onMounted(load)
 
 <template>
   <main class="workspace-page">
-    <header class="workspace-page-heading"><div><p class="eyebrow">Projects</p><h1>{{ tr('项目', 'Projects') }}</h1><p>{{ tr('从项目脉络进入会议、决策和后续行动。', 'Navigate meetings, decisions, and follow-up actions by project.') }}</p></div><button class="button button-primary" @click="openCreate">{{ tr('新建项目', 'New Project') }}</button></header>
+    <header class="workspace-page-heading"><div><p class="eyebrow">{{ tr('项目空间', 'Projects') }}</p><h1>{{ tr('项目', 'Projects') }}</h1><p>{{ tr('从项目脉络进入会议、决策和后续行动。', 'Navigate meetings, decisions, and follow-up actions by project.') }}</p></div><button class="button button-primary" @click="openCreate">{{ tr('新建项目', 'New Project') }}</button></header>
     <div class="project-filters"><label>{{ tr('项目状态', 'Status') }}<select v-model="status"><option value="">{{ tr('全部状态', 'All Statuses') }}</option><option value="active">{{ tr('进行中', 'Active') }}</option><option value="planned">{{ tr('计划中', 'Planned') }}</option><option value="paused">{{ tr('已暂停', 'Paused') }}</option><option value="completed">{{ tr('已完成', 'Completed') }}</option><option value="canceled">{{ tr('已取消', 'Canceled') }}</option></select></label><label>{{ tr('健康度', 'Health') }}<select v-model="health"><option value="">{{ tr('全部健康度', 'All Health') }}</option><option value="on_track">{{ tr('进展正常', 'On Track') }}</option><option value="at_risk">{{ tr('存在风险', 'At Risk') }}</option><option value="off_track">{{ tr('偏离计划', 'Off Track') }}</option><option value="unset">{{ tr('未设置', 'Unset') }}</option></select></label><span class="muted">{{ tr(`筛选作用于已加载项目 · ${filtered.length} 个项目`, `Filters apply to loaded projects · ${filtered.length} projects`) }}</span></div>
     <p v-if="error && !createOpen" class="notice notice-error" role="alert">{{ error }}</p>
     <p v-if="loading" class="empty-state">{{ tr('正在加载项目…', 'Loading projects…') }}</p>
diff --git a/plugins/ai-work-assistant/frontend/assistant-ui.js b/plugins/ai-work-assistant/frontend/assistant-ui.js
index 9d4b1fe..f0ec27f 100644
--- a/plugins/ai-work-assistant/frontend/assistant-ui.js
+++ b/plugins/ai-work-assistant/frontend/assistant-ui.js
@@ -1,14 +1,100 @@
 const ACTIVE_JOB_STATUSES = new Set(['queued', 'requesting'])
 const POLL_INTERVAL_MS = 3_000
 
+const EN_WORKER_ERROR_MAP = {
+  '认证或权限失败；检查管理员插件设置中的 API Key、服务地址和权限。':
+    'Authentication or permission failed; check API Key, endpoint URL, and permissions in plugin settings.',
+  'AI 服务额度不足；请充值或更换有可用额度的 API Key。':
+    'Insufficient AI service balance; please top up or replace the API Key.',
+  '找不到 AI 服务或模型；检查服务地址和模型名称。':
+    'AI service or model not found; check endpoint URL and model name.',
+  'AI 服务响应超时；请稍后重试或检查超时设置。':
+    'AI service timed out; please try again later or check timeout settings.',
+  'AI 服务限流或配额已用尽；请稍后重试并检查服务额度。':
+    'AI service rate-limited or quota exhausted; please try again later and check quota.',
+  'AI 服务返回 HTTP 状态错误。':
+    'AI service returned an HTTP status error.',
+  '无法连接 AI 服务；检查服务地址和网络。':
+    'Unable to connect to AI service; check endpoint URL and network.',
+  'AI 插件配置不完整；请联系管理员检查插件设置。':
+    'AI plugin configuration is incomplete; please check plugin settings.',
+  'AI 任务输入不符合插件要求。':
+    'AI task input does not meet plugin requirements.',
+  'AI 服务返回内容与插件格式不兼容。':
+    'AI service response is incompatible with plugin format.',
+  'AI 任务执行失败；请查看技术详情或联系管理员。':
+    'AI task execution failed; check technical details or contact an administrator.',
+  '服务重启，未重复发送 AI 请求':
+    'Server restarted; AI request was not resent',
+}
+
+const langSubscribers = new Set()
+let observersInstalled = false
+
 function isEn() {
   try {
-    return globalThis.localStorage?.getItem('meetflow_lang') === 'en'
+    if (typeof globalThis.localStorage?.getItem === 'function') {
+      const stored = globalThis.localStorage.getItem('meetflow_lang')
+      if (stored === 'en') return true
+      if (stored === 'zh') return false
+    }
+  } catch {
+    // Ignore storage errors in restricted environments.
+  }
+  try {
+    const docLang = globalThis.document?.documentElement?.lang
+    if (docLang) return docLang.toLowerCase().startsWith('en')
+  } catch {
+    // Ignore DOM errors in restricted environments.
+  }
+  return false
+}
+
+function notifyLangSubscribers(eventOrRecords) {
+  let en = isEn()
+  if (eventOrRecords && typeof eventOrRecords === 'object' && 'detail' in eventOrRecords && eventOrRecords.detail?.lang) {
+    en = eventOrRecords.detail.lang === 'en'
+  } else if (Array.isArray(eventOrRecords)) {
+    const docLang = globalThis.document?.documentElement?.lang
+    if (docLang === 'en' || docLang === 'zh') {
+      en = docLang === 'en'
+    }
+  }
+  for (const sub of langSubscribers) {
+    sub.value = en
+  }
+}
+
+function ensureLangObservers() {
+  if (observersInstalled) return
+  observersInstalled = true
+  try {
+    if (typeof globalThis.addEventListener === 'function') {
+      globalThis.addEventListener('meetflow:lang-change', notifyLangSubscribers)
+      globalThis.addEventListener('storage', notifyLangSubscribers)
+    }
+    if (typeof MutationObserver !== 'undefined' && globalThis.document?.documentElement) {
+      const observer = new MutationObserver(notifyLangSubscribers)
+      observer.observe(globalThis.document.documentElement, {
+        attributes: true,
+        attributeFilter: ['lang'],
+      })
+    }
   } catch {
-    return false
+    // Ignore observer errors in restricted environments.
   }
 }
 
+function createReactiveLangGetter(vue) {
+  ensureLangObservers()
+  if (vue && typeof vue.ref === 'function') {
+    const langSignal = vue.ref(isEn())
+    langSubscribers.add(langSignal)
+    return () => langSignal.value
+  }
+  return isEn
+}
+
 const assistantDefinitions = [
   {
     slot: 'meeting-summary-editor',
@@ -100,12 +186,17 @@ async function waitForTerminalJob(request, submittedJob) {
   return job
 }
 
-function failureMessage(jobOrError) {
+function failureMessage(jobOrError, en = isEn()) {
+  let raw = ''
   if (jobOrError && typeof jobOrError === 'object' && typeof jobOrError.error_message === 'string') {
-    return jobOrError.error_message
+    raw = jobOrError.error_message
+  } else if (jobOrError instanceof Error && jobOrError.message) {
+    raw = jobOrError.message
+  }
+  if (raw) {
+    return en ? (EN_WORKER_ERROR_MAP[raw] || raw) : raw
   }
-  if (jobOrError instanceof Error && jobOrError.message) return jobOrError.message
-  return isEn() ? 'AI generation failed, please try again later' : 'AI 生成失败，请稍后重试'
+  return en ? 'AI generation failed, please try again later' : 'AI 生成失败，请稍后重试'
 }
 
 function createAssistantComponent(pluginApi, definition) {
@@ -124,6 +215,7 @@ function createAssistantComponent(pluginApi, definition) {
     emits: ['update:modelValue', 'update:busy', 'notice'],
     setup(props, { emit }) {
       const running = ref(false)
+      const reactiveIsEn = createReactiveLangGetter(vue)
 
       const setBusy = (active, label = '') => emit('update:busy', { active, label })
       const notice = (message) => emit('notice', message)
@@ -131,7 +223,8 @@ function createAssistantComponent(pluginApi, definition) {
       async function run() {
         if (running.value) return
         running.value = true
-        const busyText = isEn() ? definition.busyLabelEn : definition.busyLabel
+        const enNow = reactiveIsEn()
+        const busyText = enNow ? definition.busyLabelEn : definition.busyLabel
         setBusy(true, busyText)
         try {
           const context = contextFor(props, definition.targetType)
@@ -146,16 +239,16 @@ function createAssistantComponent(pluginApi, definition) {
           })
           const job = await waitForTerminalJob(request, submittedJob)
           if (job.status !== 'succeeded') {
-            notice(failureMessage(job))
+            notice(failureMessage(job, reactiveIsEn()))
             return
           }
           if (typeof job.result?.markdown !== 'string') {
-            notice(isEn() ? 'AI returned no usable result' : 'AI 未返回可用结果')
+            notice(reactiveIsEn() ? 'AI returned no usable result' : 'AI 未返回可用结果')
             return
           }
           emit('update:modelValue', job.result.markdown)
         } catch (error) {
-          notice(failureMessage(error))
+          notice(failureMessage(error, reactiveIsEn()))
         } finally {
           running.value = false
           setBusy(false)
@@ -163,7 +256,7 @@ function createAssistantComponent(pluginApi, definition) {
       }
 
       return () => {
-        const en = isEn()
+        const en = reactiveIsEn()
         return h('div', { class: 'ai-work-assistant-control' }, [
           h('div', { class: 'ai-work-assistant-menu-heading' }, [
             h('span', { class: 'ai-work-assistant-menu-title' }, en ? definition.menuTitleEn : definition.menuTitle),
@@ -189,14 +282,18 @@ function createTaskExtension(pluginApi) {
   return {
     props: { job: { type: Object, required: true } },
     setup(props) {
+      const reactiveIsEn = createReactiveLangGetter(vue)
       // Keep the card quiet for jobs without a result (failed/queued): an empty
       // "查看 AI 结果" disclosure would only add noise next to the error message.
-      return () => (props.job.result?.markdown
-        ? h('details', { class: 'ai-work-assistant-task' }, [
-          h('summary', isEn() ? 'View AI Result' : '查看 AI 结果'),
-          h('pre', props.job.result.markdown),
-        ])
-        : null)
+      return () => {
+        const en = reactiveIsEn()
+        return props.job.result?.markdown
+          ? h('details', { class: 'ai-work-assistant-task' }, [
+            h('summary', en ? 'View AI Result' : '查看 AI 结果'),
+            h('pre', props.job.result.markdown),
+          ])
+          : null
+      }
     },
   }
 }
diff --git a/plugins/meeting-export/plugin.yaml b/plugins/meeting-export/plugin.yaml
index 188281f..20c943b 100644
--- a/plugins/meeting-export/plugin.yaml
+++ b/plugins/meeting-export/plugin.yaml
@@ -3,7 +3,7 @@ name: 会议导出
 version: 1.0.0
 api_version: 2
 backend_entry: backend.py
-description: 将 bounded 会议上下文导出为 Markdown 或 JSON
+description: 将会议上下文导出为结构化 Markdown 或 JSON
 capabilities:
   exporters:
     - meeting-export.markdown