diff --git a/AGENTS.md b/AGENTS.md
index 24cc836..69a4653 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -9,6 +9,7 @@ Use `am.py` for CLI/WSGI, `logistics_chat/` for business code, and `static/css/`
 | AI | `logistics_chat/chat_service.py`: `create_chat_stream`; `logistics_chat/ai_client.py`: `post_completion` |
 | Voice input | `static/js/voice.js`: `ChatVoice.create`; `logistics_chat/speech_service.py`: `transcribe_recording`, `baidu_transcribe`; `logistics_chat/routes/speech.py` |
 | Guest identity | `static/js/visitor.js`: bootstrap and cookie recovery; `logistics_chat/visitor_service.py`: owner checks; `routes/visitor.py`: customer human support |
+| Chat drafts | `static/js/drafts.js`: `ChatDrafts.create`; `chat.js`: `flushDraft`, `restoreDraft`, startup recovery |
 | Knowledge | `logistics_chat/knowledge.py`: `knowledge_list`, `search_knowledge`; `docs/knowledge.md` |
 | Pricing | `logistics_chat/pricing.py`: `RATES`, `calc_freight`; `logistics_chat/rates_extra.py` |
 | Tracking | `logistics_chat/tracking.py`: `extract_tracking_no`, `build_track`, `CARD_PREFIX` |
@@ -54,7 +55,7 @@ Use four-space Python indentation, `snake_case`, `UPPER_SNAKE_CASE` constants, a
 
 Use `tests/test_<feature>.py` and `test_<behavior>`. Mock DeepSeek; configure temporary database/upload/backup/log paths before `create_app`. Pytest: `.\.venv\Scripts\python.exe -m pytest -v`; Linux/macOS: `.venv/bin/python -m pytest -v`.
 
-Tests run `tests/frontend/admin.test.cjs`, `chat.test.cjs`, `voice.test.cjs`, and `visitor.test.cjs` when Node.js is available; no npm dependencies. Baidu ASR uses FFmpeg on PATH or `FFMPEG_BIN`; provider calls are mocked in tests.
+Tests run `tests/frontend/admin.test.cjs`, `chat.test.cjs`, `voice.test.cjs`, `visitor.test.cjs`, and `drafts.test.cjs` when Node.js is available; no npm dependencies. Baidu ASR uses FFmpeg on PATH or `FFMPEG_BIN`; provider calls are mocked in tests.
 
 ## Commit & Pull Request Guidelines
 
diff --git a/README.md b/README.md
index 8cc878d..621ba48 100644
--- a/README.md
+++ b/README.md
@@ -250,6 +250,8 @@ data: {"d": 1}
 
 游客首次访问由浏览器生成 256 位随机 key，保存在当前站点的 localStorage；服务端只保存其哈希作为会话归属，以 HttpOnly、SameSite Cookie 校验请求。刷新或同浏览器再次打开可恢复自己的历史，其他浏览器拥有独立记录；清除站点数据后无法自动找回。存储被禁用时使用 Cookie 维持访客会话。旧版未记录归属的历史不自动分配给首位访客，继续保留给受保护的客服后台。访客只能访问、删除自己的聊天、人工会话和附件，不能凭会话编号或访客 key 查询真实订单。
 
+未发送的文字草稿按游客和会话分别保存在当前浏览器的 localStorage，当前标签页通过 sessionStorage 记录上次打开的会话；切换会话和刷新可恢复对应草稿，发送或删除会话后清理。草稿不跨设备同步，不恢复未发送的附件。浏览器禁止存储或空间不足时只在当前页面暂存，并提示刷新前保留文字；清除站点数据会同时删除草稿。历史加载失败期间禁止发送，重新选择会话或新建对话后再继续。
+
 快照 JSON 放仓库外的私有 artifacts 目录，使用明确路径导入：
 
 ```powershell
@@ -260,7 +262,7 @@ data: {"d": 1}
 
 首次启动会自动创建 `chat_history`、`messages`、`feedback`、`human_sessions`、`human_messages`、`ratings`、`agents`、`orders`、`tickets` 和 `order_test_data` 十张表，并兼容已有数据，不预置账号或订单数据。本地入口使用根目录 `history.db`，Linux 部署工厂另存至专用数据目录。客服账号需由管理员在实际环境中配置。会话备注保存在 `human_sessions.note`；消息撤回事件通过 `human_messages.recalled_id` 指向原消息，轮询客户端按编号更新。订单卡片以 `__CARD__{json}` 形式保存，前端据此恢复展示。
 
-普通导入 `am.py` 或 `logistics_chat` 不创建运行数据。显式调用 `create_app()` 或访问 WSGI 兼容入口 `am.app` 时，默认初始化 SQLite、创建正常运行日志、备份数据库并清理修改时间超过 7 天的上传文件。测试须事先配置临时数据库、附件、日志和备份目录；`INITIALIZE_RUNTIME=False` 可禁止自动初始化，此时调用方负责准备 schema。历史会话的自动清理仍已关闭。
+普通导入 `am.py` 或 `logistics_chat` 不创建运行数据。显式调用 `create_app()` 或访问 WSGI 兼容入口 `am.app` 时，默认初始化 SQLite、创建正常运行日志、备份数据库，并清理未被聊天记录引用且修改时间超过 7 天的临时上传文件。已发送附件随 AI/人工聊天记录保留；已被删除的旧文件无法恢复，页面会显示附件无法访问的提示。测试须事先配置临时数据库、附件、日志和备份目录；`INITIALIZE_RUNTIME=False` 可禁止自动初始化，此时调用方负责准备 schema。历史会话的自动清理仍已关闭。
 
 ## 当前限制
 
diff --git a/docs/architecture.md b/docs/architecture.md
index 7c581a8..c522453 100644
--- a/docs/architecture.md
+++ b/docs/architecture.md
@@ -88,6 +88,8 @@ tests/                        # 按业务模块组织的回归
 - 单文件围绕一个职责；超过约 300–400 行时检查职责，而非按行数机械拆分。报价数据保持单一来源；兼容转发不复制字典。页面脚本按页面保留既有执行顺序和全局函数，不擅自改为 ES Modules。
 - 配色、字体基线和通用控件放在 `theme.css`，页面布局放在对应 CSS。客户页通过 `body.dark` 覆盖主题令牌；新增可翻译文案加入 `chat.js` 的 `I18N`，静态文案用 `data-i18n`。调整样式后检查桌面、390px 窄屏、侧栏、聊天卡片和客服空/活动状态。
 - 客户附件预览由 `clearAttachment` 管理，轨迹展开由 `fillTrackCard` 管理。客服 `drafts` 按 `sid` 保存草稿，发送成功后只清理已确认发送的内容；常用回复仅填入草稿。`renderList` 只在展示数据变化时重绘。
+- 客户文字草稿由 `drafts.js` 的 `ChatDrafts.create` 管理，脚本在 `visitor.js` 之后、`chat.js` 之前加载；localStorage 按访客 key 和会话分条存储，sessionStorage 仅记录当前标签页的活动会话。切换前同步保存，输入防抖及页面隐藏时保存；无持久存储时使用页面内存并提示。恢复历史的异步结果受会话版本约束，加载失败禁止继续发送，删除会话同步清除其草稿。草稿不含未发送附件，不跨设备同步。
+- 人工申请由服务端以 UTC+8 判断每日 08:00–22:00 营业状态，客户手机时区不参与判断。附件清理保留 `messages` 和 `human_messages` 引用的文件，仅删除超过 7 天的未引用临时文件；读取引用失败时停止清理。附件不存在或不属于当前游客均返回相同的私有、不可缓存 404 页面，破图在聊天中显示可读提示。
 - 客户页 `resetConversation` 统一处理新建、快捷问题和历史切换；人工路由同时绑定 `humanConvId` 与当前会话版本。旧建会话、历史、人工申请和轮询的异步结果不得覆盖新话题。三个业务快捷入口开启独立 AI 对话，联系人工入口才进入人工模式；排队/接待状态常驻输入框上方，可用「返回 AI 问答」结束人工会话。人工消息确认成功后才清空草稿，失败保留输入；服务端校验可选 `conv_id` 并拒绝已关闭会话。
 - 客服工作台默认只展示会话列表和全高聊天区；统计使用原生 `details` 收在「数据概览」。`setSessionTab` 切换接待/排队列表，`setChatView` 与 `showSessionList` 控制 720px 及以下的整屏导航，不结束当前会话。`setToolsOpen` 控制默认关闭的服务资料：1200px 以上为侧栏，较窄屏为抽屉；列表入口让未选会话的手机用户也能查看留言。
 
diff --git a/logistics_chat/file_service.py b/logistics_chat/file_service.py
index a9ad101..2850a6d 100644
--- a/logistics_chat/file_service.py
+++ b/logistics_chat/file_service.py
@@ -2,21 +2,35 @@
 
 import os
 import secrets
+import re
 import time
 from datetime import datetime
+from urllib.parse import unquote
 
 from .config import get_setting
 
 
 
 def cleanup_uploads():
-    """删除 uploads/ 里 7 天前的图片"""
+    """Keep attachments referenced by chat history; expire unused uploads after 7 days."""
     try:
         udir = get_setting('UPLOAD_DIR')
         if not os.path.isdir(udir):
             return
+        from .db import connect
+        connection = connect()
+        try:
+            referenced = set()
+            rows = connection.execute("SELECT content FROM messages WHERE content LIKE '%/uploads/%' "
+                                      "UNION ALL SELECT content FROM human_messages WHERE content LIKE '%/uploads/%'")
+            for (content,) in rows:
+                referenced.update(unquote(name) for name in re.findall(r'/uploads/([A-Za-z0-9_.%-]+)', content or ''))
+        finally:
+            connection.close()
         cutoff = time.time() - 7 * 86400
         for f in os.listdir(udir):
+            if f in referenced:
+                continue
             fp = os.path.join(udir, f)
             if os.path.isfile(fp) and os.path.getmtime(fp) < cutoff:
                 os.remove(fp)
diff --git a/logistics_chat/human_service.py b/logistics_chat/human_service.py
index fcb5b73..3be083b 100644
--- a/logistics_chat/human_service.py
+++ b/logistics_chat/human_service.py
@@ -1,18 +1,21 @@
 """Human conversation lifecycle; typing state is supplied by the app."""
 
 import time
-from datetime import datetime
+from datetime import datetime, timedelta, timezone
 
 from .db import connect
 
+SERVICE_TIMEZONE = timezone(timedelta(hours=8))
+
 
 def human_request(data):
     conv_id = data.get('conv_id')
     if not conv_id:
         return ({'ok': False, 'error': 'no conv'}, 400)
-    if not 8 <= datetime.now().hour < 22:
-        return {'ok': False, 'closed': True, 'msg': '人工客服工作时间为每天8:00-22:00，当前为非工作时间，请留言'}
-    now = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
+    service_time = datetime.now(SERVICE_TIMEZONE)
+    if not 8 <= service_time.hour < 22:
+        return {'ok': False, 'closed': True, 'msg': '人工客服工作时间为每天北京时间8:00-22:00，当前为非工作时间，请留言'}
+    now = service_time.strftime('%Y-%m-%d %H:%M:%S')
     conn = connect()
     conn.execute('BEGIN IMMEDIATE')
     if not conn.execute('SELECT 1 FROM chat_history WHERE id=?', (conv_id,)).fetchone():
diff --git a/logistics_chat/routes/files.py b/logistics_chat/routes/files.py
index fb69d66..cd508f1 100644
--- a/logistics_chat/routes/files.py
+++ b/logistics_chat/routes/files.py
@@ -1,12 +1,17 @@
 """HTTP adapters for files; business logic lives in services."""
 
-from flask import Blueprint, abort, request, send_from_directory
+from flask import Blueprint, render_template, request, send_from_directory
+from werkzeug.exceptions import NotFound
 
 from .. import file_service, visitor_service
 from ..config import get_setting
 
 bp = Blueprint('files', __name__)
 
+
+def unavailable(staff=False):
+    return render_template('attachment_unavailable.html', staff=staff), 404, {'Cache-Control':'private, no-store'}
+
 @bp.route('/api/upload', methods=['POST'])
 def upload_file():
     return file_service.upload_file(request.files)
@@ -15,14 +20,20 @@ def upload_file():
 @bp.route('/uploads/<path:name>')
 def uploaded_file(name):
     if not visitor_service.owns_upload(name):
-        abort(404)
-    response = send_from_directory(get_setting('UPLOAD_DIR'), name)
+        return unavailable()
+    try:
+        response = send_from_directory(get_setting('UPLOAD_DIR'), name)
+    except NotFound:
+        return unavailable()
     response.headers['Cache-Control'] = 'private, no-store'
     return response
 
 
 @bp.route('/api/staff/uploads/<path:name>')
 def staff_uploaded_file(name):
-    response = send_from_directory(get_setting('UPLOAD_DIR'), name)
+    try:
+        response = send_from_directory(get_setting('UPLOAD_DIR'), name)
+    except NotFound:
+        return unavailable(staff=True)
     response.headers['Cache-Control'] = 'private, no-store'
     return response
diff --git a/static/css/theme.css b/static/css/theme.css
index 62e16bf..56acd66 100644
--- a/static/css/theme.css
+++ b/static/css/theme.css
@@ -81,6 +81,7 @@ svg { display: block; flex-shrink: 0; }
 .emoji-picker { position: absolute; bottom: calc(100% + 12px); left: 0; z-index: 20; display: grid; grid-template-columns: repeat(5, 1fr); width: 230px; padding: 10px; border: 1px solid var(--border); border-radius: 10px; background: var(--surface); box-shadow: var(--shadow); }
 .emoji-picker button { border: 0; border-radius: 6px; background: transparent; font-size: 22px; padding: 6px; }
 .emoji-picker button:hover { background: var(--surface-hover); }
+.attachment-unavailable { display: block; max-width: 260px; padding: 12px; border: 1px dashed var(--border); border-radius: 8px; background: var(--surface-soft); color: var(--secondary); font-size: 12px; line-height: 1.6; }
 .sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
 .empty-caption { color: var(--muted); font-size: 12px; line-height: 1.8; }
 ::-webkit-scrollbar { width: 5px; height: 5px; }
diff --git a/static/js/admin.js b/static/js/admin.js
index 97187d9..202a466 100644
--- a/static/js/admin.js
+++ b/static/js/admin.js
@@ -11,6 +11,7 @@ var typeTimer = null;
 var toolsOpen = false;
 var toolsOpener = null;
 var replyInput = document.getElementById("replyText");
+SupportUI.initAttachments(document.getElementById('chatBox'), '图片暂时无法访问，请客户重新发送附件。');
 
 function escapeText(value){
     return String(value == null ? "" : value).replace(/[&<>"']/g, function(character){
diff --git a/static/js/chat.js b/static/js/chat.js
index 6c169a8..41d511e 100644
--- a/static/js/chat.js
+++ b/static/js/chat.js
@@ -6,6 +6,28 @@ const sendBtn = document.getElementById("send-button");
 const uploadBtn = document.getElementById("upload-btn");
 const uploadInput = document.getElementById("upload-input");
 const composerStatus = document.getElementById("composer-status");
+const drafts = ChatDrafts.create({scope:VisitorSession.localKey(),storage:()=>localStorage,tabStorage:()=>sessionStorage});
+let draftTimer = null;
+let draftSnapshot = null;
+function flushDraft(){
+    if(draftTimer !== null){ clearTimeout(draftTimer); draftTimer = null; }
+    const saved = drafts.write(currentConvId, inputDom.value);
+    drafts.active(currentConvId);
+    if(!saved && inputDom.value && !composerStatus.textContent) setComposerStatus(t('draftSaveFailed'), true);
+}
+function restoreDraft(){
+    inputDom.value = drafts.read(currentConvId);
+    draftSnapshot = String(currentConvId) + '\n' + inputDom.value;
+    drafts.active(currentConvId);
+    autoGrow();
+}
+function queueDraft(){
+    const snapshot = String(currentConvId) + '\n' + inputDom.value;
+    if(snapshot === draftSnapshot) return;
+    draftSnapshot = snapshot;
+    if(draftTimer !== null) clearTimeout(draftTimer);
+    draftTimer = setTimeout(flushDraft, 250);
+}
 function focusComposer(force){
     if(force || !isNarrow() || document.activeElement === inputDom){
         inputDom.focus({preventScroll:true});
@@ -29,6 +51,7 @@ let humanSendingToken = null;
 let humanClosing = false;
 window.humanSid = 0;
 const emojiPicker = SupportUI.initEmoji(document.getElementById('emoji-toggle'), document.getElementById('emoji-panel'), inputDom, function(){ autoGrow(); });
+SupportUI.initAttachments(chatDom, ()=>t('attachmentUnavailable'));
 document.getElementById('notifications-toggle').onclick = function(){ SupportUI.enableNotifications(this); };
 
 function setComposerStatus(message, isError){
@@ -217,7 +240,7 @@ const I18N = {
         busyRetry: "服务繁忙，请稍后重试",
         sessionFail: "会话创建失败，请确认服务已启动",
         autoWelcome: "您好！欢迎咨询柏悦物流智能客服，可以咨询运费、时效或联系人工客服。订单查询将在客户账号登录并关联后开放。",
-        humanHours: "人工客服工作时间：每天 8:00-22:00。当前为非工作时间，请留言，工作时间会尽快回复您。",
+        humanHours: "人工客服工作时间：每天北京时间 8:00-22:00。当前为非工作时间，请留言，工作时间会尽快回复您。",
         offlinePrompt: "请输入您的留言：",
         offlineSaved: "留言已提交，工作时间（8:00-22:00）会尽快回复您。",
         humanClosed: "人工客服已结束，您可以继续向 AI 提问。",
@@ -233,6 +256,10 @@ const I18N = {
         humanPollFailed: "人工客服连接中断，正在重试。您可以返回 AI 继续咨询。",
         humanReturnFailed: "暂时无法结束人工会话，请重试。",
         historyLoading: "正在加载这段会话，请稍候…",
+        historyLoadFailed: "会话未加载成功，请重新选择该会话重试，或新建对话。",
+        draftRestored: "已恢复这段会话的未发送草稿。",
+        draftSaveFailed: "草稿暂时无法保存到当前浏览器，刷新前请保留输入内容。",
+        attachmentUnavailable: "图片暂时无法访问，请重新发送附件。",
         recalled: "该消息已撤回",
         ratingQuestion: "本次服务满意吗？",
         ratingThanks: "感谢您的评价！",
@@ -330,7 +357,7 @@ const I18N = {
         busyRetry: "Service busy, please try again later",
         sessionFail: "Failed to create session, please check the service is running",
         autoWelcome: "Welcome to Baiyue Logistics. Ask about rates, transit times or human support. Order lookup will be available after signing in and linking a customer account.",
-        humanHours: "Our team is available daily, 08:00–22:00. Please leave a message and we will reply during service hours.",
+        humanHours: "Our team is available daily, 08:00–22:00 China Standard Time (UTC+8). Please leave a message and we will reply during service hours.",
         offlinePrompt: "Please leave your message:",
         offlineSaved: "Message submitted. Our team will reply during service hours (08:00–22:00).",
         humanClosed: "This support session has ended. You can continue chatting with the AI assistant.",
@@ -346,6 +373,10 @@ const I18N = {
         humanPollFailed: "Support connection lost. Retrying, or you can return to AI chat.",
         humanReturnFailed: "Could not end the support session. Please try again.",
         historyLoading: "Loading this conversation. Please wait…",
+        historyLoadFailed: "Conversation could not load. Select it again to retry, or start a new chat.",
+        draftRestored: "Your unsent draft has been restored.",
+        draftSaveFailed: "Your browser could not save this draft. Keep a copy before refreshing.",
+        attachmentUnavailable: "Image unavailable. Please upload the attachment again.",
         recalled: "This message was recalled",
         ratingQuestion: "How was your support experience?",
         ratingThanks: "Thank you for your feedback!",
@@ -653,11 +684,12 @@ clearAllBtn.onclick = function(){
 if(newChatBtn){
 newChatBtn.onclick = function(){
     if(openingConv === 'clearing') return;
+    const alreadyNew = currentConvId === null;
     resetConversation(null);
-    inputDom.value = "";
+    if(alreadyNew) inputDom.value = "";
     autoGrow();
     clearAttachment();
-    setComposerStatus("");
+    setComposerStatus(inputDom.value ? t('draftRestored') : '');
     chatDom.innerHTML = welcomeHTML();
     chatDom.scrollTop = 0;
     followLatest = true;
@@ -673,10 +705,13 @@ function loadHistory(){
         historyList = data;
         renderSideHistory();
         renderRecentChat();
-    }).catch(function(){ /* 保留上次成功加载的历史，避免网络错误清空侧栏。 */ });
+        return data;
+    }).catch(function(){ return null; /* 保留上次成功加载的历史。 */ });
 }
 
 function removeCachedHistory(id){
+    if(id === undefined){ drafts.clear(); flushDraft(); }
+    else drafts.remove(id);
     historyRequestVersion += 1;
     historyList = id === undefined ? [] : historyList.filter(item => item.id !== id);
     renderSideHistory();
@@ -823,6 +858,8 @@ function ensureConv(){
                 throw error;
             }
             currentConvId = data.id;
+            drafts.remove('new');
+            flushDraft();
             if(data.welcome) addMsg(t('autoWelcome'), false);
             return currentConvId;
         }).finally(function(){ if(creatingConv === pending) creatingConv = null; });
@@ -831,6 +868,7 @@ function ensureConv(){
 }
 
 function resetConversation(id){
+    flushDraft();
     emojiPicker.close();
     if(voiceInput) voiceInput.cancel();
     if(cancelActive){ cancelActive(); cancelActive = null; }
@@ -839,6 +877,7 @@ function resetConversation(id){
     clearAttachment();
     stopHumanMode();
     currentConvId = id;
+    restoreDraft();
     openingConv = null;
     creatingConv = null;
     sendPreparing = false;
@@ -856,6 +895,7 @@ function openConversation(id){
     const version = resetConversation(id);
     if(isNarrow()){ sideOpen = false; renderSidebar(); }
     openingConv = id;
+    chatDom.innerHTML = '';
     setComposerStatus(t('historyLoading'));
     renderSideHistory();
     requestJson("/api/get_messages?conv_id=" + id)
@@ -863,7 +903,7 @@ function openConversation(id){
         if(version !== conversationVersion) return;
         if(!Array.isArray(msgs)) throw new Error('History failed');
         openingConv = null;
-        setComposerStatus('');
+        setComposerStatus(inputDom.value ? t('draftRestored') : '');
         chatDom.innerHTML = "";
         if(!msgs.length){
             chatDom.innerHTML = welcomeHTML();
@@ -886,8 +926,8 @@ function openConversation(id){
         requestAnimationFrame(function(){ scrollChatToEnd(true); });
     }).catch(function(){
         if(version !== conversationVersion) return;
-        openingConv = null;
-        setComposerStatus(t('networkFail'), true);
+        openingConv = 'failed';
+        setComposerStatus(t('historyLoadFailed'), true);
     });
 }
 
@@ -1047,7 +1087,30 @@ function addTrackCard(card, timeStr){
     return bubble;
 }
 
-loadHistory();
+const restoreId = drafts.active();
+currentConvId = restoreId === 'new' ? null : Number(restoreId);
+restoreDraft();
+if(currentConvId){
+    const id = currentConvId, version = conversationVersion, initialDraft = inputDom.value;
+    openingConv = 'restoring';
+    loadHistory().then(function(history){
+        if(version !== conversationVersion || currentConvId !== id || openingConv !== 'restoring') return;
+        if(Array.isArray(history) && !history.some(item=>item.id === id)){
+            if(inputDom.value !== initialDraft){
+                openingConv = 'failed';
+                flushDraft();
+                setComposerStatus(t('historyLoadFailed'), true);
+                return;
+            }
+            drafts.remove(id);
+            currentConvId = null;
+            restoreDraft();
+            openingConv = null;
+            return;
+        }
+        openConversation(id);
+    });
+}else loadHistory();
 
 window.fillInput = function(words){
     inputDom.value = words;
@@ -1113,11 +1176,10 @@ async function humanRequest(path, data){
 window.showHuman = async function(){
     if(voiceInput) voiceInput.cancel();
     if(openingConv === 'clearing') return;
+    if(openingConv !== null){ setComposerStatus(t(openingConv === 'failed' ? 'historyLoadFailed' : 'historyLoading'), true); return; }
     if(humanRequestToken || humanClosing) return;
     if(window.humanSid && humanConvId === currentConvId){ updateHumanMode(); return; }
     if(window.humanSid) stopHumanMode();
-    const hour = new Date().getHours();
-    if(hour < 8 || hour >= 22) return leaveOfflineMessage();
     const token = {version:conversationVersion};
     humanRequestToken = token;
     if(cancelActive){ cancelActive(); cancelActive = null; }
@@ -1530,7 +1592,7 @@ async function doSend(retryText){
     var fullContent = sendWord;
     if(imgUrl) fullContent += (fullContent ? " " : "") + tag + imgUrl;
     setComposerStatus("");
-    if(openingConv !== null){ setComposerStatus(t('historyLoading')); return; }
+    if(openingConv !== null){ setComposerStatus(t(openingConv === 'failed' ? 'historyLoadFailed' : 'historyLoading'), true); return; }
     if(humanRequestToken || humanClosing){ updateHumanMode(); return; }
     // 人工客服模式：直接发给客服，不走AI
     if(window.humanSid && humanConvId === currentConvId) return sendHumanMessage(fullContent);
@@ -1764,6 +1826,7 @@ sendBtn.addEventListener("click", function(){
 
 // ===== 多行输入框：自动增高 =====
 function autoGrow(){
+    queueDraft();
     if(!inputDom.value){
         inputDom.style.height = '';
         return;
@@ -1775,6 +1838,8 @@ function autoGrow(){
     inputDom.style.height = Math.min(inputDom.scrollHeight, limit) + "px";
 }
 inputDom.addEventListener("input", autoGrow);
+window.addEventListener('pagehide', flushDraft);
+document.addEventListener('visibilitychange', function(){ if(document.hidden) flushDraft(); });
 
 inputDom.addEventListener("keydown",(e)=>{
     // Enter 发送，Shift+Enter 换行
diff --git a/static/js/drafts.js b/static/js/drafts.js
new file mode 100644
index 0000000..be9b055
--- /dev/null
+++ b/static/js/drafts.js
@@ -0,0 +1,77 @@
+// Text drafts stay in this visitor's browser, independently for each conversation.
+var ChatDrafts = {
+    create(options){
+        const scope = /^[0-9a-f]{64}$/.test(options.scope || '') ? options.scope : null;
+        const prefix = scope ? 'baiyue-draft-v1:' + scope + ':' : null;
+        const activeKey = scope ? 'baiyue-active-chat-v1:' + scope : null;
+        const memory = new Map();
+        const dirty = new Set();
+        let current = 'new';
+        function id(value){
+            if(value === null || value === 'new') return 'new';
+            const key = String(value);
+            return /^[1-9][0-9]{0,18}$/.test(key) ? key : null;
+        }
+        function storage(name){
+            try{ return options[name](); }catch(error){ return null; }
+        }
+        function read(value){
+            const key = id(value);
+            if(!key) return '';
+            if(dirty.has(key)) return memory.get(key) || '';
+            if(prefix){
+                try{
+                    const saved = storage('storage').getItem(prefix + key);
+                    if(saved !== null){
+                        const data = JSON.parse(saved);
+                        if(data && data.version === 1 && typeof data.text === 'string'){
+                            memory.set(key, data.text);
+                            return data.text;
+                        }
+                    }
+                    memory.delete(key);
+                    return '';
+                }catch(error){}
+            }
+            return memory.get(key) || '';
+        }
+        function write(value, text){
+            const key = id(value);
+            if(!key || typeof text !== 'string') return false;
+            if(text) memory.set(key, text); else memory.delete(key);
+            dirty.add(key);
+            if(!prefix) return false;
+            try{
+                const target = storage('storage');
+                if(text) target.setItem(prefix + key, JSON.stringify({version:1,text:text}));
+                else target.removeItem(prefix + key);
+                dirty.delete(key);
+                return true;
+            }catch(error){ return false; }
+        }
+        function active(value){
+            if(arguments.length){
+                current = id(value) || 'new';
+                if(activeKey) try{ storage('tabStorage').setItem(activeKey, current); }catch(error){}
+            }else if(activeKey){
+                try{ const saved=storage('tabStorage').getItem(activeKey); if(saved !== null) current = id(saved) || current; }catch(error){}
+            }
+            return current;
+        }
+        function clear(){
+            memory.clear();
+            dirty.clear();
+            if(prefix){
+                try{
+                    const target = storage('storage');
+                    for(let index = target.length - 1; index >= 0; index--){
+                        const key = target.key(index);
+                        if(key && key.startsWith(prefix)) target.removeItem(key);
+                    }
+                }catch(error){}
+            }
+            active('new');
+        }
+        return {read:read,write:write,active:active,remove:value=>write(value,''),clear:clear};
+    }
+};
diff --git a/static/js/support.js b/static/js/support.js
index b66c548..a3a97d7 100644
--- a/static/js/support.js
+++ b/static/js/support.js
@@ -1,5 +1,17 @@
 // Shared controls for the customer page and service workspace.
 var SupportUI = {
+    initAttachments(container, label){
+        container.addEventListener('error', function(event){
+            const image = event.target;
+            if(!image || image.tagName !== 'IMG' || !image.classList.contains('message-image') || image.dataset.unavailable) return;
+            image.dataset.unavailable = '1';
+            image.hidden = true;
+            const hint = document.createElement('span');
+            hint.className = 'attachment-unavailable';
+            hint.textContent = typeof label === 'function' ? label() : label;
+            image.after(hint);
+        }, true);
+    },
     async enableNotifications(button){
         if(!('Notification' in window)) return;
         try{
diff --git a/static/js/visitor.js b/static/js/visitor.js
index 8b1cf1a..ee53d63 100644
--- a/static/js/visitor.js
+++ b/static/js/visitor.js
@@ -45,5 +45,5 @@ var VisitorSession = (function(){
         }
         return established ? send() : ensure().then(send);
     }
-    return {fetch:request};
+    return {fetch:request,localKey:localKey};
 })();
diff --git a/templates/attachment_unavailable.html b/templates/attachment_unavailable.html
new file mode 100644
index 0000000..b53d344
--- /dev/null
+++ b/templates/attachment_unavailable.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<html lang="zh-CN">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>附件暂时无法访问 · 柏悦物流</title>
+    <link rel="stylesheet" href="{{ url_for('static', filename='css/theme.css') }}">
+    <style>
+        body { min-height: 100vh; min-height: 100dvh; display: grid; place-items: center; padding: 24px; }
+        main { width: min(420px, 100%); padding: 28px; border: 1px solid var(--border); border-radius: 16px; background: var(--surface); }
+        h1 { font-size: 22px; margin-bottom: 14px; }
+        p { color: var(--secondary); margin: 10px 0; }
+        .english { font-size: 13px; }
+        a { display: inline-block; margin-top: 12px; }
+    </style>
+</head>
+<body><main>
+    <h1>附件暂时无法访问</h1>
+    <p>文件可能已过期、被删除或当前无法访问。请返回会话重新发送，或联系人工客服。</p>
+    <p lang="en" class="english">This attachment is unavailable. Please return to your conversation to upload it again or contact support.</p>
+    <a href="{{ url_for('admin.admin_dash') if staff else url_for('pages.index') }}">{{ '返回客服工作台' if staff else '返回聊天' }}</a>
+</main></body>
+</html>
diff --git a/templates/index.html b/templates/index.html
index 3f2a7a0..780050b 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -74,6 +74,7 @@
 </div>
 <script src="{{ url_for('static', filename='js/support.js') }}"></script>
 <script src="{{ url_for('static', filename='js/visitor.js') }}"></script>
+<script src="{{ url_for('static', filename='js/drafts.js') }}"></script>
 <script src="{{ url_for('static', filename='js/voice.js') }}"></script>
 <script src="{{ url_for('static', filename='js/chat.js') }}"></script>
 </body>
diff --git a/tests/frontend/chat.test.cjs b/tests/frontend/chat.test.cjs
index 3420226..3fa32c2 100644
--- a/tests/frontend/chat.test.cjs
+++ b/tests/frontend/chat.test.cjs
@@ -6,6 +6,14 @@ const vm = require('node:vm');
 const flush = () => new Promise(setImmediate);
 
 async function customerPage(pageOptions = {}){
+    const storageValues = pageOptions.storage || {};
+    if(!storageValues['baiyue-visitor-key']) storageValues['baiyue-visitor-key']='1'.repeat(64);
+    const tabValues = pageOptions.tabStorage || {};
+    function testStorage(values){return {
+        getItem:key=>values[key] ?? null,setItem:(key,value)=>{values[key]=String(value);},
+        removeItem:key=>{delete values[key];},key:index=>Object.keys(values)[index] ?? null,
+        get length(){return Object.keys(values).length;}
+    };}
     const elements = new Map(), listeners = {}, windowListeners = {}, viewportListeners = {}, intervals = new Map(), timers = new Map(), calls = [], hooks = {};
     let intervalId = 0, timerId = 0, nextConvId = 1;
     let voiceOptions;
@@ -71,7 +79,7 @@ async function customerPage(pageOptions = {}){
         document, console, Date:TestDate, navigator:{language:'zh-CN',clipboard:pageOptions.clipboard}, AbortController, TextDecoder, confirm:() => true,
         FormData:class { append(){} },
         requestAnimationFrame:callback => callback(),
-        localStorage:{getItem:key => (pageOptions.storage || {})[key] ?? null, setItem(){}},
+        localStorage:testStorage(storageValues),sessionStorage:testStorage(tabValues),
         window:{innerWidth:pageOptions.width || 1200, innerHeight:pageOptions.viewportHeight || pageOptions.height || 800,
             addEventListener:(name,callback) => { (windowListeners[name] ||= []).push(callback); },
             matchMedia:query => ({matches:context.window.innerWidth <= Number((query.match(/max-width:\s*(\d+)px/) || [])[1])}),
@@ -85,6 +93,7 @@ async function customerPage(pageOptions = {}){
         fetch: async (url, options) => {
             calls.push({url, body:options && options.body && (typeof options.body === 'string' ? JSON.parse(options.body) : options.body)});
             if(hooks[url]) return hooks[url](options);
+            if(url === '/api/get_history' && pageOptions.historyFetch) return pageOptions.historyFetch();
             if(url.startsWith('/api/visitor/human/poll') && hooks.poll) return hooks.poll(url);
             if(url.startsWith('/api/get_messages') && hooks.messages) return hooks.messages(url);
             if(url === '/stream_chat'){
@@ -97,14 +106,14 @@ async function customerPage(pageOptions = {}){
             }
             const data = url === '/api/new_chat' ? {id:nextConvId++, welcome:'welcome'}
                 : url === '/api/visitor/session' ? {ok:true,key:'1'.repeat(64)}
-                : url === '/api/visitor/human/request' ? {ok:true, session_id:7}
+                : url === '/api/visitor/human/request' ? (pageOptions.serviceClosed ? {ok:false,closed:true} : {ok:true, session_id:7})
                 : url.startsWith('/api/visitor/human/poll') ? state
                 : ['/api/rate', '/api/feedback', '/api/visitor/human/send', '/api/visitor/human/close', '/api/ticket'].includes(url) || url.startsWith('/api/del_history') ? {ok:true}
                 : url === '/api/get_history' ? (pageOptions.history || []) : [];
             return {ok:true, json:async () => data};
         },
     });
-    for(const file of ['support.js', 'visitor.js', 'voice.js', 'chat.js']){
+    for(const file of ['support.js', 'visitor.js', 'drafts.js', 'voice.js', 'chat.js']){
         vm.runInContext(fs.readFileSync(path.join(__dirname, '../../static/js', file), 'utf8'), context, {filename:file});
         if(file === 'voice.js'){
             const createVoice=context.ChatVoice.create;
@@ -115,7 +124,7 @@ async function customerPage(pageOptions = {}){
     await flush();
     if(pageOptions.human !== false) await context.window.showHuman();
     await flush();
-    return {context, element, calls, hooks, quickButtons, voiceOptions,
+    return {context, element, calls, hooks, quickButtons, voiceOptions,storage:storageValues,tabStorage:tabValues,
         documentEvent:(name,event)=>{ if(listeners[name]) listeners[name](event); },
         resize:async height => {
             context.window.innerHeight=height;
@@ -134,6 +143,7 @@ async function customerPage(pageOptions = {}){
             await flush();
         },
         pageShow:async () => { (windowListeners.pageshow || []).forEach(callback => callback()); await flush(); },
+        pageHide:async () => { (windowListeners.pagehide || []).forEach(callback => callback()); await flush(); },
         setState:value => { state=value; },
         runTimers:async delay => { for(const [id, timer] of Array.from(timers)) if(timer.delay === delay){ timers.delete(id); timer.callback(); } await flush(); },
         tick:async () => { Array.from(intervals.values()).forEach(callback => callback()); await flush(); },
@@ -488,9 +498,9 @@ test('repeated contact clicks create one human request and show a visible queue
 });
 
 test('the contact shortcut outside service hours submits a ticket without entering human mode', async () => {
-    const app = await customerPage({human:false, hour:23, offlineMessage:'请明天跟进报价'});
+    const app = await customerPage({human:false, hour:12,serviceClosed:true, offlineMessage:'请明天跟进报价'});
     await app.context.window.showHuman();
-    assert.equal(app.calls.filter(call => call.url === '/api/visitor/human/request').length, 0);
+    assert.equal(app.calls.filter(call => call.url === '/api/visitor/human/request').length, 1);
     assert.equal(app.calls.find(call => call.url === '/api/ticket').body.content, '请明天跟进报价');
     assert.match(app.element('chatDom').textContent, /留言已提交/);
     assert.equal(app.context.window.humanSid, 0);
@@ -505,6 +515,13 @@ test('a failed human send preserves the text and makes retry possible', async ()
     assert.equal(app.element('send-button').disabled, false);
 });
 
+test('a visitor whose phone says late at night can still reach an open support service', async () => {
+    const app=await customerPage({human:false,hour:23});
+    await app.context.window.showHuman();
+    assert.equal(app.context.window.humanSid,7);
+    assert.equal(app.calls.filter(call=>call.url==='/api/ticket').length,0);
+});
+
 test('a duplicate human send cannot submit an in-flight message twice', async () => {
     const app = await customerPage();
     let resolve;
@@ -841,10 +858,10 @@ test('successful clipboard fallback reports copied and keeps text focus stable',
 });
 
 test('blank offline messages are ignored and invalid ticket text stays editable with a readable error', async () => {
-    const empty=await customerPage({human:false,hour:23,offlineMessage:'   '});
+    const empty=await customerPage({human:false,hour:23,serviceClosed:true,offlineMessage:'   '});
     await empty.context.window.showHuman();await flush();
     assert.equal(empty.calls.filter(call=>call.url==='/api/ticket').length,0);
-    const app=await customerPage({human:false,hour:23,offlineMessage:'需要保留的留言'});
+    const app=await customerPage({human:false,hour:23,serviceClosed:true,offlineMessage:'需要保留的留言'});
     app.hooks['/api/ticket']=()=>response({ok:false,error:'请输入 1–2000 字的留言。'},400);
     await app.context.window.showHuman();await flush();
     assert.equal(app.element('input-text').value,'需要保留的留言');
@@ -879,3 +896,99 @@ test('emoji panel dismisses outside or on Escape, stays open for its own control
     await app.click(app.element('.new-chat-btn'));
     assert.equal(panel.hidden,true);
 });
+
+test('drafts stay with their own conversation and restore across a page reload', async () => {
+    const history=[{id:9,title:'A',ctime:'now'},{id:10,title:'B',ctime:'now'}];
+    const app=await customerPage({human:false,history});
+    await app.click(app.element('historyWrap').children[0]);
+    app.element('input-text').value='A的未发送草稿';app.element('input-text').listeners.input();
+    await app.click(app.element('historyWrap').children[1]);
+    assert.equal(app.element('input-text').value,'');
+    app.element('input-text').value='B的未发送草稿';app.element('input-text').listeners.input();
+    await app.click(app.element('historyWrap').children[0]);
+    assert.equal(app.element('input-text').value,'A的未发送草稿');
+    await app.pageHide();
+    const restored=await customerPage({human:false,history,storage:app.storage,tabStorage:app.tabStorage});
+    await flush();
+    assert.equal(restored.element('input-text').value,'A的未发送草稿');
+    assert.ok(restored.calls.some(call=>call.url==='/api/get_messages?conv_id=9'));
+    await restored.click(restored.element('historyWrap').children[1]);
+    assert.equal(restored.element('input-text').value,'B的未发送草稿');
+});
+
+test('a new conversation draft restores after refresh and moves to the created conversation on send', async () => {
+    const app=await customerPage({human:false});
+    app.element('input-text').value='尚未发送';app.element('input-text').listeners.input();await app.pageHide();
+    const restored=await customerPage({human:false,storage:app.storage,tabStorage:app.tabStorage});
+    assert.equal(restored.element('input-text').value,'尚未发送');
+    await restored.context.window.fillInput('尚未发送');await restored.pageHide();
+    const store=restored.context.ChatDrafts.create({scope:'1'.repeat(64),storage:()=>restored.context.localStorage,tabStorage:()=>restored.context.sessionStorage});
+    assert.equal(store.read(null),'');assert.equal(store.read(1),'');assert.equal(store.active(),'1');
+});
+
+test('restoring an old conversation cannot replace a newer user-selected draft', async () => {
+    const app=await customerPage({human:false,history:[{id:9,title:'A',ctime:'now'}]});
+    await app.click(app.element('historyWrap').children[0]);
+    app.element('input-text').value='A草稿';app.element('input-text').listeners.input();await app.pageHide();
+    let release;
+    const restored=await customerPage({human:false,storage:app.storage,tabStorage:app.tabStorage,
+        historyFetch:()=>new Promise(resolve=>{release=resolve;})});
+    await restored.click(restored.element('.new-chat-btn'));
+    restored.element('input-text').value='新话题草稿';restored.element('input-text').listeners.input();
+    release(response([{id:9,title:'A',ctime:'now'}]));await flush();
+    assert.equal(restored.element('input-text').value,'新话题草稿');
+});
+
+test('failed history loading cannot send a question under a hidden conversation context', async () => {
+    const app=await customerPage({human:false,history:[{id:9,title:'A',ctime:'now'}]});
+    await app.context.window.fillInput('原会话');await flush();
+    app.hooks.messages=()=>response({ok:false},503);
+    await app.click(app.element('historyWrap').children[0]);
+    const before=app.calls.filter(call=>call.url==='/stream_chat').length;
+    await app.context.window.fillInput('禁止发到未加载会话');
+    assert.equal(app.calls.filter(call=>call.url==='/stream_chat').length,before);
+    assert.match(app.element('composer-status').textContent,/会话未加载成功/);
+    assert.doesNotMatch(app.element('chatDom').textContent,/原会话/);
+});
+
+test('startup removes a deleted active conversation draft without erasing a newer edit', async () => {
+    const app=await customerPage({human:false,history:[{id:9,title:'A',ctime:'now'}]});
+    await app.click(app.element('historyWrap').children[0]);
+    app.element('input-text').value='旧会话草稿';app.element('input-text').listeners.input();await app.pageHide();
+    const noEdit=await customerPage({human:false,storage:{...app.storage},tabStorage:{...app.tabStorage}});
+    assert.equal(noEdit.element('input-text').value,'');
+    assert.ok(!noEdit.calls.some(call=>call.url==='/api/get_messages?conv_id=9'));
+    let release;
+    const edited=await customerPage({human:false,storage:app.storage,tabStorage:app.tabStorage,
+        historyFetch:()=>new Promise(resolve=>{release=resolve;})});
+    edited.element('input-text').value='加载期间的新输入';edited.element('input-text').listeners.input();
+    release(response([]));await flush();
+    assert.equal(edited.element('input-text').value,'加载期间的新输入');
+    await edited.context.window.fillInput('加载期间的新输入');
+    assert.ok(!edited.calls.some(call=>call.url==='/stream_chat'));
+    assert.match(edited.element('composer-status').textContent,/会话未加载成功/);
+});
+
+test('deleting a conversation removes only its saved draft', async () => {
+    const history=[{id:9,title:'A',ctime:'now'},{id:10,title:'B',ctime:'now'}];
+    const app=await customerPage({human:false,history});
+    await app.click(app.element('historyWrap').children[0]);
+    app.element('input-text').value='A草稿';app.element('input-text').listeners.input();
+    await app.click(app.element('historyWrap').children[1]);
+    app.element('input-text').value='B草稿';app.element('input-text').listeners.input();await app.pageHide();
+    await app.element('historyWrap').children[0].children[2].onclick({stopPropagation(){}});
+    const store=app.context.ChatDrafts.create({scope:'1'.repeat(64),storage:()=>app.context.localStorage,tabStorage:()=>app.context.sessionStorage});
+    assert.equal(store.read(9),'');assert.equal(store.read(10),'B草稿');
+});
+
+test('an unavailable image gets one readable replacement instead of a broken image', async () => {
+    const app=await customerPage({human:false});
+    let shown;
+    const image={tagName:'IMG',classList:{contains:name=>name==='message-image'},dataset:{},after:hint=>{shown=hint;}};
+    app.element('chatDom').listeners.error({target:image});
+    assert.equal(image.hidden,true);
+    assert.match(shown.textContent,/图片暂时无法访问/);
+    const first=shown;
+    app.element('chatDom').listeners.error({target:image});
+    assert.equal(shown,first);
+});
diff --git a/tests/frontend/drafts.test.cjs b/tests/frontend/drafts.test.cjs
new file mode 100644
index 0000000..7027097
--- /dev/null
+++ b/tests/frontend/drafts.test.cjs
@@ -0,0 +1,48 @@
+const test=require('node:test');
+const assert=require('node:assert/strict');
+const fs=require('node:fs');
+const vm=require('node:vm');
+const path=require('node:path');
+const context=vm.createContext({});
+vm.runInContext(fs.readFileSync(path.join(__dirname,'../../static/js/drafts.js'),'utf8'),context);
+function storage(){
+    const data=new Map();
+    return {data,get length(){return data.size;},key:index=>Array.from(data.keys())[index] ?? null,
+        getItem:key=>data.get(key) ?? null,setItem:(key,value)=>data.set(key,value),removeItem:key=>data.delete(key)};
+}
+function drafts(scope='1'.repeat(64),local=storage(),tab=storage()){
+    return context.ChatDrafts.create({scope,storage:()=>local,tabStorage:()=>tab});
+}
+test('conversation drafts and active tab restore independently of another visitor or tab',()=>{
+    const local=storage(),tab=storage(),a=drafts(undefined,local,tab);
+    a.write(9,'A');a.write(10,'B');a.write(null,'NEW');a.active(9);
+    const restored=drafts(undefined,local,tab);
+    assert.equal(restored.read(9),'A');assert.equal(restored.read(10),'B');assert.equal(restored.read(null),'NEW');
+    assert.equal(restored.active(),'9');
+    const otherTab=drafts(undefined,local);otherTab.write(10,'B updated');
+    assert.equal(otherTab.active(),'new');assert.equal(restored.read(10),'B updated');assert.equal(restored.read(9),'A');
+    otherTab.remove(10);assert.equal(restored.read(10),'');
+    assert.equal(drafts('2'.repeat(64),local,tab).read(9),'');
+});
+test('malformed records and invalid identifiers cannot become restored drafts',()=>{
+    const local=storage(),a=drafts(undefined,local),key='baiyue-draft-v1:'+'1'.repeat(64)+':9';
+    for(const value of ['null','{"version":2,"text":"old"}','{"version":1,"text":45}']){
+        local.setItem(key,value);assert.equal(a.read(9),'');
+    }
+    assert.equal(a.write('../9','invalid'),false);assert.equal(a.read('../9'),'');
+});
+test('removing and clearing a visitor never clears another visitor or unrelated preferences',()=>{
+    const local=storage(),a=drafts(undefined,local),b=drafts('2'.repeat(64),local);
+    local.setItem('theme','dark');a.write(9,'A');a.write(10,'B');b.write(9,'PRIVATE');
+    a.remove(9);assert.equal(a.read(9),'');assert.equal(a.read(10),'B');
+    a.clear();assert.equal(a.read(10),'');assert.equal(b.read(9),'PRIVATE');assert.equal(local.getItem('theme'),'dark');
+});
+test('blocked storage and quota errors retain the latest in-memory draft without a shared bucket',()=>{
+    const broken={getItem(){throw Error();},setItem(){throw Error();},removeItem(){throw Error();}};
+    const a=drafts(undefined,broken,broken);
+    assert.equal(a.write(9,'latest'),false);assert.equal(a.read(9),'latest');a.active(9);assert.equal(a.active(),'9');
+    const local=storage(),b=drafts(undefined,local);b.write(9,'old');
+    local.setItem=()=>{throw Error('quota');};assert.equal(b.write(9,'new'),false);assert.equal(b.read(9),'new');
+    const anonymous=drafts(null,local);anonymous.write(9,'memory only');assert.equal(anonymous.read(9),'memory only');
+    assert.equal(drafts(null,local).read(9),'');
+});
diff --git a/tests/test_dev_integration.py b/tests/test_dev_integration.py
index c9bd7e6..146778f 100644
--- a/tests/test_dev_integration.py
+++ b/tests/test_dev_integration.py
@@ -1,6 +1,6 @@
 """Remote dev behavior on the modular backend and the light workspace."""
 
-from datetime import datetime
+from datetime import datetime, timezone
 import io
 from pathlib import Path
 import tempfile
@@ -50,6 +50,19 @@ class DevIntegrationTests(unittest.TestCase):
         self.assertEqual(self.client.post('/api/ticket', json={'content': '周末留言'}).json, {'ok': True})
         self.assertEqual(self.client.get('/api/tickets').json[0]['content'], '周末留言')
 
+    def test_service_hours_use_china_time_even_when_the_host_clock_is_utc(self):
+        cid = self.client.post('/api/new_chat').json['id']
+        for utc_hour, expected in ((0, True),(13, True),(14, False),(23, False)):
+            instant = datetime(2026,10,31,utc_hour,tzinfo=timezone.utc)
+            class HostUtcClock(datetime):
+                @classmethod
+                def now(cls, tz=None):
+                    return instant.astimezone(tz) if tz else instant.replace(tzinfo=None)
+            with self.subTest(utc_hour=utc_hour), patch('logistics_chat.human_service.datetime', HostUtcClock):
+                result = self.client.post('/api/visitor/human/request',json={'conv_id':cid}).json
+                self.assertEqual(result['ok'],expected)
+                if not expected: self.assertTrue(result['closed'])
+
     def test_transfer_returns_to_queue_preserves_messages_and_note(self):
         sid = self.session()
         self.client.post('/api/human/accept', json={'sid': sid})
diff --git a/tests/test_frontend.py b/tests/test_frontend.py
index cb57c88..55cdff4 100644
--- a/tests/test_frontend.py
+++ b/tests/test_frontend.py
@@ -11,7 +11,7 @@ class FrontendTests(unittest.TestCase):
     def test_reply_workflows(self):
         root = Path(__file__).resolve().parents[1]
         result = subprocess.run(
-            ['node', '--test', 'tests/frontend/admin.test.cjs', 'tests/frontend/chat.test.cjs', 'tests/frontend/voice.test.cjs', 'tests/frontend/visitor.test.cjs'], cwd=root,
+            ['node', '--test', 'tests/frontend/admin.test.cjs', 'tests/frontend/chat.test.cjs', 'tests/frontend/voice.test.cjs', 'tests/frontend/visitor.test.cjs', 'tests/frontend/drafts.test.cjs'], cwd=root,
             text=True, encoding='utf-8', capture_output=True, timeout=30,
         )
         self.assertEqual(result.returncode, 0, result.stdout + result.stderr)
diff --git a/tests/test_storage.py b/tests/test_storage.py
index 7483502..c1ea0c5 100644
--- a/tests/test_storage.py
+++ b/tests/test_storage.py
@@ -123,6 +123,20 @@ class StorageTests(unittest.TestCase):
         self.assertNotIn('..', name)
         self.assertFalse(result['is_image'])
 
+    def test_old_attachments_referenced_by_ai_or_human_history_survive_cleanup(self):
+        uploads=self.root/'uploads'; uploads.mkdir()
+        for name in ('ai.png','human.pdf','unused.txt'):
+            file=uploads/name;file.write_bytes(b'fixture')
+            os.utime(file,(time.time()-20*86400,time.time()-20*86400))
+        connection=db.connect()
+        connection.execute("INSERT INTO messages(conv_id,role,content,ctime) VALUES(1,'user','[图片]/uploads/ai.png','now')")
+        connection.execute("INSERT INTO human_messages(session_id,side,content,ctime) VALUES(1,'customer','[文件]/uploads/human.pdf','now')")
+        connection.commit();connection.close()
+        file_service.cleanup_uploads()
+        self.assertTrue((uploads/'ai.png').exists())
+        self.assertTrue((uploads/'human.pdf').exists())
+        self.assertFalse((uploads/'unused.txt').exists())
+
     def test_invalid_and_oversized_uploads_are_rejected(self):
         self.assertEqual(file_service.upload_file({})[1], 400)
         denied = FileStorage(stream=io.BytesIO(b'bad'), filename='test.exe')
diff --git a/tests/test_visitor.py b/tests/test_visitor.py
index c03f23a..dd1d5e0 100644
--- a/tests/test_visitor.py
+++ b/tests/test_visitor.py
@@ -125,6 +125,17 @@ class VisitorTests(unittest.TestCase):
             self.assertIn('客户账号登录并关联',response.get_data(as_text=True))
             lookup.assert_not_called();model.assert_not_called()
 
+    def test_missing_attachments_show_a_readable_private_page_without_disclosing_ownership(self):
+        response=self.a.post('/api/upload',data={'file':(io.BytesIO(b'fixture'),'missing.txt')})
+        url=response.json['url']
+        (Path(self.app.config['UPLOAD_DIR'])/url.rsplit('/',1)[1]).unlink()
+        own=self.a.get(url);other=self.b.get(url)
+        self.assertEqual(own.status_code,404)
+        self.assertIn('附件暂时无法访问',own.get_data(as_text=True))
+        self.assertIn('no-store',own.headers['Cache-Control'])
+        self.assertEqual(own.data,other.data)
+        self.assertNotIn(url,own.get_data(as_text=True))
+
     def test_invalid_bootstrap_and_cross_site_requests_cannot_replace_the_guest(self):
         cid=self.conversation(self.a,'A_PRIVATE')
         for key in ('short','x'*64,'1'*65,[],{},123):