feat: improve cross-conversation reply UX

.cbmignore

@@ -0,0 +1,43 @@
+# codebase-memory-mcp 专用忽略规则。
+# 保留源码级 public/app.js、public/style.css 等文件；只排除生成物、压缩物和临时产物。
+
+# 依赖、运行态数据和日志（多数已在 .gitignore，这里显式补强）
+node_modules/
+sessions/
+logs/
+attachments/
+config/cross-conversation-replies.json
+
+# 构建与覆盖率产物
+dist/
+build/
+coverage/
+.cache/
+.parcel-cache/
+.vite/
+.next/
+.nuxt/
+
+# 压缩、归档和二进制产物
+*.zip
+*.tar
+*.tar.gz
+*.tgz
+*.gz
+*.7z
+*.rar
+
+# 前端生成物：保留普通源码，只排除压缩/映射/打包结果
+*.min.js
+*.min.css
+*.bundle.js
+*.bundle.css
+*.map
+
+# 临时文件
+*.tmp
+*.temp
+*.bak
+*.swp
+*.log
+* TO DO list.csv

.codex/config.toml

@@ -0,0 +1,8 @@
+[mcp_servers.codebase-memory-mcp]
+type = "stdio"
+command = "/home/hdzx/.local/bin/codebase-memory-mcp"
+args = []
+enabled = true
+startup_timeout_sec = 20
+tool_timeout_sec = 120
+env = { CBM_LOG_LEVEL = "info", CBM_CACHE_DIR = "/home/hdzx/.cache/codebase-memory-mcp" }

AGENTS.md

@@ -25,10 +25,74 @@ Keep this managed block so 'trellis update' can refresh the instructions.
 
 重启 cc-web 服务：
 
+修改 ccweb 项目后如果需要重启服务，必须先查看当前会话列表中的运行状态。
+只有在除当前对话外没有其他 `running` 对话时，才能执行重启；如果仍有其他
+运行中的对话，应暂缓重启并告知用户原因。
+
 ```bash
 pm2 restart ccweb --update-env
 ```
 
+## Codebase Memory 代码检索约定
+
+本项目内 **graphify 已全面弃用**。后续涉及代码定位、调用链、架构理解、影响面分析、跨模块关系梳理时，默认优先使用 `codebase-memory-mcp`，不要再启用 graphify 技能、graphify CLI 或 `graphify-out` 产物作为主路径。
+
+当前项目的 codebase-memory 项目名：
+
+```text
+home-cc-web
+```
+
+### 默认检索流程
+
+1. 先确认索引状态：
+   - `list_projects`
+   - `index_status(project="home-cc-web")`
+2. 如果索引缺失或明显过期，先执行：
+   - `index_repository(repo_path="/home/cc-web", mode="full", persistence=false)`
+3. 需要理解整体结构时，先用：
+   - `get_architecture(project="home-cc-web", aspects=["all"])`
+4. 需要找功能入口、类、函数、路由时，优先用：
+   - `search_graph`
+   - `search_code`
+5. 需要确认调用关系时，使用：
+   - `trace_path(mode="calls", direction="inbound" | "outbound" | "both")`
+6. 需要读取具体实现时，先通过 `search_graph` 找到精确 `qualified_name`，再用：
+   - `get_code_snippet`
+7. `rg` / `sed` 只作为补充校验：
+   - 校验最终行号
+   - 查未被索引的配置或纯文本
+   - 对 MCP 命中结果做交叉验证
+
+### 子代理引导词模板
+
+派发需要理解代码的子代理时，默认加入以下引导：
+
+```text
+请优先使用 codebase-memory-mcp 做代码理解：
+先 list_projects / index_status 确认项目索引；
+再用 search_graph 或 search_code 定位候选函数；
+需要调用链时用 trace_path；
+需要源码时先拿 qualified_name，再调用 get_code_snippet；
+最后只用 rg/sed 校验行号或补查未索引文本。
+不要使用 graphify。
+```
+
+### 本项目已验证的使用经验
+
+- 无明确引导时，子代理不一定会主动使用 `codebase-memory-mcp`，可能退回 `rg` 或旧的 graphify 路径。
+- 明确要求优先使用 `codebase-memory-mcp` 后，能稳定命中函数级入口、调用链和源码片段。
+- 对 `codexapp` / `ccweb` 这类跨模块链路，`search_code` + `trace_path` + `get_code_snippet` 的组合比单纯全文检索更快建立上下文。
+- 自然语言检索遇到 `developer`、`config`、`message` 等通用词会有噪声；这时应收敛到明确标识符，如 `collaborationMode`、`mcp_servers.ccweb`、`CC_WEB_SOURCE_SESSION_ID`。
+- 最终答复中的文件行号仍建议用 `rg -n` 或 `nl -ba` 做一次轻量核验。
+
+### 索引更新与忽略规则
+
+- `auto_index` 是 `codebase-memory-mcp` 的本地配置，按当前 `CBM_CACHE_DIR` 生效；它不是 `.codex/config.toml` 里的项目级开关。
+- 当前项目的项目级忽略规则写在 `.cbmignore`。普通源码级 `*.js` / `*.css` 不应一刀切排除；只排除 `*.min.js`、`*.map`、压缩包、构建目录、日志、临时文件、运行态状态文件等。
+- watcher 是 Git-based polling：非 Git 项目跳过轮询；Git 项目的轮询间隔为基础 5 秒，每 500 个文件加 1 秒，最长 60 秒。
+- 修改 `.cbmignore` 或大范围调整文件后，建议手动执行一次 `index_repository(repo_path="/home/cc-web", mode="full", persistence=false)`，让当前索引立即收敛到最新规则。
+
 ## Codex App / hapi 对齐经验
 
 以下约定来自本项目对 `/home/hdzx/2026/hapi` 中 Codex app-server 接入方式的对比结果。后续如果继续维护 `codexapp`，默认按这些约定实现，避免再走偏到“看起来能跑、但拿不到原生协作能力”的分叉路径。

config/cross-conversation-replies.json

@@ -0,0 +1,5 @@
+{
+  "version": 1,
+  "updatedAt": "2026-06-21T15:06:34.507Z",
+  "replies": []
+}

public/app.js

@@ -2,12 +2,42 @@
 (function () {
   'use strict';
 
-  const ASSET_VERSION = '20260618-mobile-session-switch';
+  const ASSET_VERSION = '20260621-cross-reply-collapse-last-section-offset';
   const WS_URL = `${location.protocol === 'https:' ? 'wss' : 'ws'}://${location.host}/ws`;
   const RENDER_DEBOUNCE = 100;
   const COMPOSER_SUGGESTION_DEBOUNCE = 120;
   const DIVIDER_TIME_STORAGE_KEY = 'cc-web-show-divider-time';
   const PROJECT_COLLAPSE_STORAGE_KEY = 'cc-web-collapsed-projects';
+  const CROSS_CONVERSATION_REPLY_COLLAPSE_STORAGE_KEY = 'cc-web-collapsed-cross-replies';
+  const CROSS_CONVERSATION_REPLY_COLLAPSE_LIMIT = 500;
+  const ASSISTANT_LAST_SECTION_BUTTON_CLASS = 'msg-last-section-btn';
+  const ASSISTANT_LAST_SECTION_FOCUS_CLASS = 'msg-last-section-focus';
+  const ASSISTANT_LAST_SECTION_SCROLL_OFFSET = 72;
+  const ASSISTANT_LAST_SECTION_SKIP_SELECTOR = [
+    `.${ASSISTANT_LAST_SECTION_BUTTON_CLASS}`,
+    '.msg-tools',
+    '.tool-call',
+    '.tool-group',
+    '.msg-attachments',
+    '.msg-attachment-card',
+    '.cross-conversation-meta',
+    '.agent-message-divider',
+  ].join(',');
+  const ASSISTANT_LAST_SECTION_SCOPE_SELECTOR = [
+    'p',
+    'li',
+    'h1',
+    'h2',
+    'h3',
+    'h4',
+    'h5',
+    'h6',
+    'td',
+    'th',
+    'pre',
+    'code',
+    '.msg-text',
+  ].join(',');
 
   const SLASH_COMMANDS = [
     { cmd: '/clear', desc: '清除当前会话' },
@@ -178,6 +208,14 @@
       return new Set();
     }
   })();
+  const collapsedCrossConversationReplyKeys = (() => {
+    try {
+      const parsed = JSON.parse(localStorage.getItem(CROSS_CONVERSATION_REPLY_COLLAPSE_STORAGE_KEY) || '[]');
+      return new Set(Array.isArray(parsed) ? parsed.filter(Boolean) : []);
+    } catch {
+      return new Set();
+    }
+  })();
   const pendingNotesByTarget = new Map();
   const userMessageIndex = new Map();
   const expandedOldSessionAgents = new Set();
@@ -815,6 +853,51 @@
     return value.length > maxLength ? `${value.slice(0, maxLength - 1)}…` : value;
   }
 
+  function getCrossConversationReplyCollapseKey(meta = {}) {
+    const source = meta?.crossConversation || {};
+    const messageId = source.replyToRequestId
+      || source.messageId
+      || meta.messageId
+      || meta.id
+      || [source.sourceSessionId, meta.timestamp || source.processedAt || source.sentAt].filter(Boolean).join(':');
+    if (!messageId) return '';
+    return `${currentSessionId || 'unknown'}:${messageId}`;
+  }
+
+  function persistCrossConversationReplyCollapseState() {
+    try {
+      const keys = Array.from(collapsedCrossConversationReplyKeys).slice(-CROSS_CONVERSATION_REPLY_COLLAPSE_LIMIT);
+      localStorage.setItem(CROSS_CONVERSATION_REPLY_COLLAPSE_STORAGE_KEY, JSON.stringify(keys));
+    } catch {}
+  }
+
+  function setCrossConversationReplyCollapsed(key, collapsed) {
+    if (!key) return;
+    if (collapsed) {
+      collapsedCrossConversationReplyKeys.delete(key);
+      collapsedCrossConversationReplyKeys.add(key);
+    } else {
+      collapsedCrossConversationReplyKeys.delete(key);
+    }
+    persistCrossConversationReplyCollapseState();
+  }
+
+  function isCrossConversationReplyCollapsed(key) {
+    return !!key && collapsedCrossConversationReplyKeys.has(key);
+  }
+
+  function formatCrossConversationReplyTime(value) {
+    if (!value) return '';
+    const date = new Date(value);
+    if (Number.isNaN(date.getTime())) return '';
+    return date.toLocaleString('zh-CN', {
+      month: '2-digit',
+      day: '2-digit',
+      hour: '2-digit',
+      minute: '2-digit',
+    });
+  }
+
   function createLocalId(prefix = 'local') {
     if (window.crypto?.randomUUID) return `${prefix}-${window.crypto.randomUUID()}`;
     return `${prefix}-${Date.now()}-${Math.random().toString(36).slice(2, 10)}`;
@@ -893,6 +976,166 @@
     messagesDiv.scrollTo({ top: Math.max(0, targetTop), behavior: 'smooth' });
   }
 
+  function isAssistantLastSectionTextNode(node, root) {
+    if (!node || node.nodeType !== Node.TEXT_NODE || !node.nodeValue?.trim()) return false;
+    const parent = node.parentElement;
+    if (!parent || !root.contains(parent)) return false;
+    if (parent.closest(ASSISTANT_LAST_SECTION_SKIP_SELECTOR)) return false;
+    const tag = parent.tagName?.toLowerCase();
+    return !['button', 'script', 'style', 'textarea', 'input', 'select', 'option'].includes(tag);
+  }
+
+  function collectAssistantTextNodes(root) {
+    const nodes = [];
+    if (!root) return nodes;
+    const walker = document.createTreeWalker(root, NodeFilter.SHOW_TEXT, {
+      acceptNode(node) {
+        return isAssistantLastSectionTextNode(node, root)
+          ? NodeFilter.FILTER_ACCEPT
+          : NodeFilter.FILTER_REJECT;
+      },
+    });
+    let node = walker.nextNode();
+    while (node) {
+      nodes.push(node);
+      node = walker.nextNode();
+    }
+    return nodes;
+  }
+
+  function findLastAssistantTextScope(bubble) {
+    const nodes = collectAssistantTextNodes(bubble);
+    const lastNode = nodes[nodes.length - 1];
+    if (!lastNode) return null;
+    return lastNode.parentElement?.closest(ASSISTANT_LAST_SECTION_SCOPE_SELECTOR) || bubble;
+  }
+
+  function collectAssistantTextScopes(root) {
+    if (!root) return [];
+    const seen = new Set();
+    return Array.from(root.querySelectorAll(ASSISTANT_LAST_SECTION_SCOPE_SELECTOR)).filter((scope) => {
+      if (!scope || seen.has(scope)) return false;
+      seen.add(scope);
+      if (scope.closest(ASSISTANT_LAST_SECTION_SKIP_SELECTOR)) return false;
+      return collectAssistantTextNodes(scope).length > 0;
+    });
+  }
+
+  function findFirstAssistantTextScopeAfterDivider(bubble) {
+    const dividers = Array.from(bubble?.querySelectorAll?.('.agent-message-divider') || []);
+    const lastDivider = dividers[dividers.length - 1];
+    if (!lastDivider) return null;
+    return collectAssistantTextScopes(bubble).find((scope) => (
+      lastDivider.compareDocumentPosition(scope) & Node.DOCUMENT_POSITION_FOLLOWING
+    )) || null;
+  }
+
+  function findFirstNonWhitespaceIndex(text, start = 0) {
+    for (let i = Math.max(0, start); i < text.length; i += 1) {
+      if (!/\s/.test(text[i])) return i;
+    }
+    return -1;
+  }
+
+  function mapTextIndexToNode(entries, index) {
+    for (const entry of entries) {
+      if (index >= entry.start && index < entry.end) {
+        return { node: entry.node, offset: index - entry.start };
+      }
+    }
+    const last = entries[entries.length - 1];
+    return last ? { node: last.node, offset: last.node.nodeValue.length } : null;
+  }
+
+  function getAssistantTextScopeStartTarget(scope) {
+    if (!scope) return null;
+    const nodes = collectAssistantTextNodes(scope);
+    if (nodes.length === 0) return null;
+    const entries = [];
+    let text = '';
+    nodes.forEach((node) => {
+      const value = node.nodeValue || '';
+      const start = text.length;
+      text += value;
+      entries.push({ node, start, end: text.length });
+    });
+    const startIndex = findFirstNonWhitespaceIndex(text, 0);
+    if (startIndex < 0) return null;
+    const mapped = mapTextIndexToNode(entries, startIndex);
+    return mapped ? { ...mapped, scope } : null;
+  }
+
+  function getAssistantLastSectionTarget(bubble) {
+    const scope = findFirstAssistantTextScopeAfterDivider(bubble) || findLastAssistantTextScope(bubble);
+    return getAssistantTextScopeStartTarget(scope);
+  }
+
+  function getRangeRectFromTextPosition(node, offset) {
+    if (!node) return null;
+    const range = document.createRange();
+    const safeOffset = Math.min(Math.max(0, offset), node.nodeValue.length);
+    range.setStart(node, safeOffset);
+    range.setEnd(node, Math.min(node.nodeValue.length, safeOffset + 1));
+    const rect = Array.from(range.getClientRects()).find(item => item.width || item.height) || null;
+    range.detach?.();
+    return rect;
+  }
+
+  function scrollAssistantBubbleToLastSection(bubble) {
+    const target = getAssistantLastSectionTarget(bubble);
+    if (!target) return false;
+    const rect = getRangeRectFromTextPosition(target.node, target.offset) || target.scope.getBoundingClientRect();
+    if (!rect) return false;
+    const containerRect = messagesDiv.getBoundingClientRect();
+    const targetTop = messagesDiv.scrollTop + rect.top - containerRect.top - ASSISTANT_LAST_SECTION_SCROLL_OFFSET;
+    messagesDiv.scrollTo({ top: Math.max(0, targetTop), behavior: 'smooth' });
+    target.scope.classList.remove(ASSISTANT_LAST_SECTION_FOCUS_CLASS);
+    requestAnimationFrame(() => {
+      target.scope.classList.add(ASSISTANT_LAST_SECTION_FOCUS_CLASS);
+      window.setTimeout(() => target.scope.classList.remove(ASSISTANT_LAST_SECTION_FOCUS_CLASS), 1100);
+    });
+    updateScrollbar();
+    return true;
+  }
+
+  function createAssistantLastSectionButton() {
+    const button = document.createElement('button');
+    button.type = 'button';
+    button.className = ASSISTANT_LAST_SECTION_BUTTON_CLASS;
+    button.title = '定位到本条回复最后一段';
+    button.setAttribute('aria-label', '定位到本条回复最后一段');
+    button.innerHTML = `
+      <svg width="15" height="15" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true">
+        <circle cx="12" cy="12" r="7"></circle>
+        <circle cx="12" cy="12" r="2"></circle>
+        <path d="M12 2v3"></path>
+        <path d="M12 19v3"></path>
+        <path d="M2 12h3"></path>
+        <path d="M19 12h3"></path>
+      </svg>
+    `;
+    button.addEventListener('click', (event) => {
+      event.preventDefault();
+      event.stopPropagation();
+      const bubble = button.closest('.msg-bubble');
+      scrollAssistantBubbleToLastSection(bubble);
+    });
+    return button;
+  }
+
+  function syncAssistantLastSectionButton(messageEl) {
+    if (!messageEl?.classList?.contains('assistant')) return;
+    const bubble = messageEl.querySelector(':scope > .msg-bubble');
+    if (!bubble) return;
+    let button = bubble.querySelector(`:scope > .${ASSISTANT_LAST_SECTION_BUTTON_CLASS}`);
+    const hasTarget = !!getAssistantLastSectionTarget(bubble);
+    if (!button && !hasTarget) return;
+    if (!button) button = createAssistantLastSectionButton();
+    button.hidden = !hasTarget;
+    button.disabled = !hasTarget;
+    bubble.appendChild(button);
+  }
+
   function updateSessionIdBadge() {
     if (!chatSessionIdBtn) return;
     if (!currentSessionId) {
@@ -907,24 +1150,70 @@
     chatSessionIdBtn.setAttribute('aria-label', `复制当前会话 ID ${currentSessionId}`);
   }
 
+  function shouldPreferTextareaCopy() {
+    const ua = navigator.userAgent || '';
+    return /iPad|iPhone|iPod/.test(ua)
+      || (navigator.platform === 'MacIntel' && navigator.maxTouchPoints > 1);
+  }
+
+  function copyTextWithTextarea(value) {
+    const textarea = document.createElement('textarea');
+    textarea.value = value;
+    textarea.setAttribute('readonly', '');
+    textarea.setAttribute('aria-hidden', 'true');
+    textarea.style.position = 'fixed';
+    textarea.style.top = '0';
+    textarea.style.left = '0';
+    textarea.style.width = '1px';
+    textarea.style.height = '1px';
+    textarea.style.padding = '0';
+    textarea.style.border = '0';
+    textarea.style.opacity = '0';
+    textarea.style.pointerEvents = 'none';
+    textarea.style.fontSize = '16px';
+    document.body.appendChild(textarea);
+
+    const activeElement = document.activeElement;
+    try {
+      try {
+        textarea.focus({ preventScroll: true });
+      } catch {
+        textarea.focus();
+      }
+      textarea.select();
+      try {
+        textarea.setSelectionRange(0, value.length);
+      } catch {}
+      if (!document.execCommand('copy')) throw new Error('copy_failed');
+    } finally {
+      textarea.remove();
+      if (activeElement && typeof activeElement.focus === 'function') {
+        try {
+          activeElement.focus({ preventScroll: true });
+        } catch {}
+      }
+    }
+  }
+
   async function copyTextToClipboard(text, successText = '已复制') {
     const value = String(text || '');
     if (!value) return false;
     try {
-      if (navigator.clipboard?.writeText && window.isSecureContext) {
-        await navigator.clipboard.writeText(value);
-      } else {
-        const textarea = document.createElement('textarea');
-        textarea.value = value;
-        textarea.setAttribute('readonly', '');
-        textarea.style.position = 'fixed';
-        textarea.style.left = '-9999px';
-        textarea.style.top = '0';
-        document.body.appendChild(textarea);
-        textarea.select();
-        document.execCommand('copy');
-        textarea.remove();
+      let copied = false;
+      const preferTextarea = shouldPreferTextareaCopy();
+      if (preferTextarea) {
+        try {
+          copyTextWithTextarea(value);
+          copied = true;
+        } catch {}
       }
+      if (!copied && navigator.clipboard?.writeText && window.isSecureContext) {
+        try {
+          await navigator.clipboard.writeText(value);
+          copied = true;
+        } catch {}
+      }
+      if (!copied) copyTextWithTextarea(value);
       showToast(successText);
       return true;
     } catch {
@@ -3008,7 +3297,7 @@
     }
     const canPreview = PREVIEW_LANGS.has(lang);
     const previewBtn = canPreview
-      ? `<button class="code-preview-btn" onclick="ccTogglePreview(this)">Preview</button>`
+      ? `<button class="code-preview-btn" type="button" onclick="ccTogglePreview(this, event)" aria-label="预览代码块">Preview</button>`
       : '';
     const previewPane = canPreview
       ? `<div class="code-preview-pane"><iframe class="code-preview-iframe" sandbox="allow-scripts" loading="lazy"></iframe></div>`
@@ -3018,24 +3307,37 @@
     return `<div class="code-block-wrapper${canPreview ? ' has-preview' : ''}"${canPreview ? ` data-cid="${cid}"` : ''}>
       <div class="code-block-header">
         <span>${escapeHtml(lang)}</span>
-        <div class="code-block-actions">${previewBtn}<button class="code-copy-btn" onclick="ccCopyCode(this)">Copy</button></div>
+        <div class="code-block-actions">${previewBtn}<button class="code-copy-btn" type="button" onclick="ccCopyCode(this, event)" aria-label="复制代码块">Copy</button></div>
       </div>
       ${previewPane}<pre><code class="hljs language-${escapeHtml(lang)}">${highlighted}</code></pre>
     </div>`;
   };
   marked.setOptions({ renderer, breaks: true, gfm: true });
 
-  window.ccCopyCode = function (btn) {
-    const wrapper = btn.closest('.code-block-wrapper');
+  window.ccCopyCode = async function (btn, event) {
+    event?.preventDefault();
+    event?.stopPropagation();
+    const wrapper = btn?.closest?.('.code-block-wrapper');
+    if (!wrapper) return;
     const cid = wrapper.dataset.cid ? Number(wrapper.dataset.cid) : 0;
-    const code = (cid && _previewCodeMap.has(cid)) ? _previewCodeMap.get(cid) : wrapper.querySelector('code').textContent;
-    navigator.clipboard.writeText(code).then(() => {
-      btn.textContent = 'Copied!';
-      setTimeout(() => btn.textContent = 'Copy', 1500);
-    });
+    const code = (cid && _previewCodeMap.has(cid)) ? _previewCodeMap.get(cid) : wrapper.querySelector('code')?.textContent;
+    const defaultLabel = btn.dataset.defaultLabel || btn.textContent || 'Copy';
+    btn.dataset.defaultLabel = defaultLabel;
+    btn.disabled = true;
+    const copied = await copyTextToClipboard(code, '代码已复制');
+    btn.disabled = false;
+    if (!copied) return;
+    if (btn._copyResetTimer) clearTimeout(btn._copyResetTimer);
+    btn.textContent = 'Copied!';
+    btn._copyResetTimer = setTimeout(() => {
+      btn.textContent = btn.dataset.defaultLabel || 'Copy';
+      btn._copyResetTimer = null;
+    }, 1500);
   };
 
-  window.ccTogglePreview = function (btn) {
+  window.ccTogglePreview = function (btn, event) {
+    event?.preventDefault();
+    event?.stopPropagation();
     const wrapper = btn.closest('.code-block-wrapper');
     const inPreview = wrapper.classList.contains('preview-mode');
     if (inPreview) {
@@ -3617,6 +3919,7 @@
     toolsDiv.className = 'msg-tools';
     bubble.appendChild(textDiv);
     bubble.appendChild(toolsDiv);
+    syncAssistantLastSectionButton(msgEl);
     messagesDiv.appendChild(msgEl);
     scrollToBottom();
     return true;
@@ -3666,6 +3969,7 @@
         }
       }
       streamEl.removeAttribute('id');
+      syncAssistantLastSectionButton(streamEl);
     }
 
     if (sessionId) {
@@ -3702,6 +4006,7 @@
       if (!textDiv) { textDiv = bubble; }
       textDiv.innerHTML = renderMarkdown(pendingText);
     }
+    syncAssistantLastSectionButton(streamEl);
     scrollToBottom();
   }
 
@@ -3877,6 +4182,7 @@
     const div = document.createElement('div');
     const isCrossConversation = !!meta.crossConversation;
     const isCrossConversationReply = isCrossConversation && !!(meta.crossConversation.reply || meta.crossConversation.replyToRequestId);
+    const canCollapseCrossConversationReply = role === 'assistant' && isCrossConversationReply;
     const resolvedMessageId = meta?.messageId || meta?.id || createLocalId('user');
     div.className = `msg ${role}${role === 'assistant' ? ' agent-' + currentAgent : ''}${isCrossConversation ? ' cross-conversation' : ''}${isCrossConversationReply ? ' cross-conversation-reply' : ''}`;
     if (role === 'user') {
@@ -3932,6 +4238,28 @@
 
     const bubble = document.createElement('div');
     bubble.className = 'msg-bubble';
+    let crossConversationReplyCollapseKey = '';
+    let crossConversationReplyToggle = null;
+    let crossConversationReplyBody = null;
+
+    const applyCrossConversationReplyCollapseState = (collapsed) => {
+      if (!crossConversationReplyToggle || !crossConversationReplyBody) return;
+      div.classList.toggle('cross-conversation-collapsed', collapsed);
+      bubble.dataset.collapsed = collapsed ? 'true' : 'false';
+      crossConversationReplyBody.hidden = collapsed;
+      crossConversationReplyToggle.textContent = collapsed ? '展开' : '收起';
+      crossConversationReplyToggle.title = collapsed ? '展开返回消息' : '收起返回消息';
+      crossConversationReplyToggle.setAttribute('aria-label', collapsed ? '展开返回消息' : '收起返回消息');
+      crossConversationReplyToggle.setAttribute('aria-expanded', String(!collapsed));
+      updateScrollbar();
+    };
+
+    if (canCollapseCrossConversationReply) {
+      crossConversationReplyCollapseKey = getCrossConversationReplyCollapseKey(meta);
+      if (crossConversationReplyCollapseKey) {
+        div.dataset.crossConversationReplyKey = crossConversationReplyCollapseKey;
+      }
+    }
 
     if (isCrossConversation) {
       const source = meta.crossConversation || {};
@@ -3960,6 +4288,27 @@
         sourceMeta.appendChild(copyBtn);
       }
 
+      if (canCollapseCrossConversationReply) {
+        const replyTimeText = formatCrossConversationReplyTime(meta.timestamp || source.processedAt || source.sentAt);
+        if (replyTimeText) {
+          const time = document.createElement('span');
+          time.className = 'cross-conversation-time';
+          time.textContent = replyTimeText;
+          sourceMeta.appendChild(time);
+        }
+
+        crossConversationReplyToggle = document.createElement('button');
+        crossConversationReplyToggle.type = 'button';
+        crossConversationReplyToggle.className = 'cross-conversation-collapse-btn';
+        crossConversationReplyToggle.addEventListener('click', (event) => {
+          event.stopPropagation();
+          const collapsed = !div.classList.contains('cross-conversation-collapsed');
+          setCrossConversationReplyCollapsed(crossConversationReplyCollapseKey, collapsed);
+          applyCrossConversationReplyCollapseState(collapsed);
+        });
+        sourceMeta.appendChild(crossConversationReplyToggle);
+      }
+
       bubble.appendChild(sourceMeta);
     }
 
@@ -3994,15 +4343,29 @@
       const mentionsStrip = renderComposerMentionsStrip(meta);
       if (mentionsStrip) bubble.appendChild(mentionsStrip);
     } else {
-      renderAssistantContent(bubble, content);
+      const assistantContentTarget = canCollapseCrossConversationReply ? document.createElement('div') : bubble;
+      if (canCollapseCrossConversationReply) {
+        assistantContentTarget.className = 'cross-conversation-reply-body';
+        crossConversationReplyBody = assistantContentTarget;
+      }
+      renderAssistantContent(assistantContentTarget, content);
       if (attachments.length > 0) {
-        bubble.insertAdjacentHTML('beforeend', renderAttachmentPreviews(attachments));
+        assistantContentTarget.insertAdjacentHTML('beforeend', renderAttachmentPreviews(attachments));
+      }
+      if (canCollapseCrossConversationReply) {
+        bubble.appendChild(assistantContentTarget);
       }
     }
 
     hydrateAttachmentPreviews(bubble, attachments);
     div.appendChild(avatar);
     div.appendChild(bubble);
+    if (role === 'assistant') {
+      syncAssistantLastSectionButton(div);
+    }
+    if (canCollapseCrossConversationReply) {
+      applyCrossConversationReplyCollapseState(isCrossConversationReplyCollapsed(crossConversationReplyCollapseKey));
+    }
     if (role === 'user' && meta.codexAppSteerStatus) {
       setCodexAppSteerStatusElement(div, meta.codexAppSteerStatus, meta.codexAppSteerMessage);
     }
@@ -4699,6 +5062,7 @@
 	    const el = createMsgElement(m.role, m.content, m.attachments || [], m);
 	    if (m.role === 'assistant' && m.toolCalls && m.toolCalls.length > 0) {
 	      const bubble = el.querySelector('.msg-bubble');
+	      const toolMount = bubble.querySelector(':scope > .cross-conversation-reply-body') || bubble;
 	      const FOLD_AT = 3;
 	      let grouped = false;
 	      const mergedCollabTool = mergeCollabAgentTools(m.toolCalls);
@@ -4711,9 +5075,9 @@
 	        const details = createToolCallElement(tc.id || `saved-${Math.random().toString(36).slice(2)}`, tc, true);
 
 	        // 散落的 .tool-call 达到 FOLD_AT 个时，移入唯一 .tool-group
-        const loose = Array.from(bubble.children).filter(isGroupableToolCall);
+        const loose = Array.from(toolMount.children).filter(isGroupableToolCall);
         if (loose.length >= FOLD_AT) {
-          let group = bubble.querySelector(':scope > .tool-group');
+          let group = toolMount.querySelector(':scope > .tool-group');
           if (!group) {
             group = document.createElement('details');
             group.className = 'tool-group';
@@ -4723,20 +5087,20 @@
             const inner = document.createElement('div');
             inner.className = 'tool-group-inner';
             group.appendChild(inner);
-            bubble.insertBefore(group, bubble.firstChild);
+            toolMount.insertBefore(group, toolMount.firstChild);
             grouped = true;
           }
           const inner = group.querySelector('.tool-group-inner');
           loose.forEach(c => inner.appendChild(c));
           _refreshGroupSummary(group);
         }
-        bubble.appendChild(details);
+        toolMount.appendChild(details);
       }
       // 结束时若出现过父目录，收尾散落项
       if (grouped) {
-        const loose = Array.from(bubble.children).filter(isGroupableToolCall);
+        const loose = Array.from(toolMount.children).filter(isGroupableToolCall);
         if (loose.length > 0) {
-          const group = bubble.querySelector(':scope > .tool-group');
+          const group = toolMount.querySelector(':scope > .tool-group');
           if (group) {
             const inner = group.querySelector('.tool-group-inner');
             loose.forEach(c => inner.appendChild(c));

public/index.html

@@ -14,7 +14,7 @@
       document.documentElement.dataset.dividerTime = dividerTime;
     })();
   </script>
-  <link rel="stylesheet" href="style.css?v=20260617-skill-openai-yaml">
+  <link rel="stylesheet" href="style.css?v=20260621-cross-reply-collapse-last-section-offset">
   <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/styles/atom-one-dark.min.css">
 </head>
 <body>
@@ -154,6 +154,6 @@
 
   <script src="https://cdnjs.cloudflare.com/ajax/libs/marked/12.0.1/marked.min.js"></script>
   <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/highlight.min.js"></script>
-  <script src="app.js?v=20260618-mobile-session-switch"></script>
+  <script src="app.js?v=20260621-cross-reply-collapse-last-section-offset"></script>
 </body>
 </html>

public/style.css

@@ -2279,19 +2279,24 @@ body.session-loading-active {
   border-color: rgba(93, 138, 84, 0.28);
 }
 .msg.cross-conversation-reply .cross-conversation-meta,
-.msg.cross-conversation-reply .cross-conversation-id-btn {
+.msg.cross-conversation-reply .cross-conversation-id-btn,
+.msg.cross-conversation-reply .cross-conversation-collapse-btn,
+.msg.cross-conversation-reply .cross-conversation-time {
   color: var(--success);
 }
-.msg.cross-conversation-reply .cross-conversation-id-btn {
+.msg.cross-conversation-reply .cross-conversation-id-btn,
+.msg.cross-conversation-reply .cross-conversation-collapse-btn {
   border-color: rgba(93, 138, 84, 0.28);
 }
-.msg.cross-conversation-reply .cross-conversation-id-btn:hover {
+.msg.cross-conversation-reply .cross-conversation-id-btn:hover,
+.msg.cross-conversation-reply .cross-conversation-collapse-btn:hover {
   background: rgba(93, 138, 84, 0.14);
 }
 .cross-conversation-meta {
   display: flex;
   align-items: center;
   gap: 8px;
+  row-gap: 6px;
   flex-wrap: wrap;
   margin-bottom: 7px;
   color: var(--info);
@@ -2299,10 +2304,19 @@ body.session-loading-active {
   font-weight: 800;
 }
 .cross-conversation-label {
+  flex: 1 1 180px;
   min-width: 0;
   overflow-wrap: anywhere;
 }
-.cross-conversation-id-btn {
+.cross-conversation-time {
+  flex-shrink: 0;
+  color: var(--text-muted);
+  font-size: 10px;
+  font-weight: 700;
+  white-space: nowrap;
+}
+.cross-conversation-id-btn,
+.cross-conversation-collapse-btn {
   appearance: none;
   border: 1px solid rgba(91, 126, 161, 0.24);
   border-radius: 999px;
@@ -2313,15 +2327,72 @@ body.session-loading-active {
   font-size: 10px;
   cursor: pointer;
 }
-.cross-conversation-id-btn:hover {
+.cross-conversation-collapse-btn {
+  min-width: 44px;
+}
+.cross-conversation-id-btn:hover,
+.cross-conversation-collapse-btn:hover {
   background: rgba(91, 126, 161, 0.14);
 }
+.cross-conversation-collapse-btn:focus-visible {
+  outline: 2px solid rgba(93, 138, 84, 0.28);
+  outline-offset: 2px;
+}
+.msg.cross-conversation-collapsed .cross-conversation-meta {
+  margin-bottom: 0;
+}
+.msg.cross-conversation-collapsed .msg-last-section-btn {
+  display: none;
+}
 .msg.assistant .msg-bubble {
   background: var(--bg-bubble-assistant);
   border: 1px solid var(--border-color);
   border-bottom-left-radius: 4px;
   color: var(--text-primary);
 }
+.msg-last-section-btn {
+  appearance: none;
+  width: 28px;
+  height: 28px;
+  margin: 8px 0 0 auto;
+  padding: 0;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  border: 1px solid var(--border-color);
+  border-radius: 8px;
+  background: var(--bg-secondary);
+  color: var(--text-secondary);
+  cursor: pointer;
+  opacity: 0.72;
+  transition: opacity 0.15s ease, background 0.15s ease, border-color 0.15s ease, color 0.15s ease, transform 0.15s ease;
+}
+.msg-last-section-btn[hidden] {
+  display: none;
+}
+.msg-last-section-btn svg {
+  display: block;
+  flex-shrink: 0;
+}
+.msg-last-section-btn:hover {
+  opacity: 1;
+  background: var(--bg-tertiary);
+  border-color: var(--accent);
+  color: var(--accent);
+  transform: translateY(-1px);
+}
+.msg-last-section-btn:focus-visible {
+  opacity: 1;
+  outline: 2px solid rgba(91, 126, 161, 0.28);
+  outline-offset: 2px;
+}
+.msg-last-section-focus {
+  animation: lastSectionFocus 1.1s ease;
+}
+@keyframes lastSectionFocus {
+  0% { background: rgba(91, 126, 161, 0.18); }
+  100% { background: transparent; }
+}
 .msg.assistant .msg-mention-chip {
   border-color: rgba(48, 62, 82, 0.14);
   background: rgba(91, 126, 161, 0.07);
@@ -2577,26 +2648,50 @@ html[data-divider-time='hide'] .msg-bubble .agent-message-divider span {
   display: flex;
   justify-content: space-between;
   align-items: center;
+  gap: 8px;
   padding: 6px 12px;
   background: #2b2b2b;
   font-size: 12px;
   color: #999;
 }
+.code-block-header > span {
+  min-width: 0;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
 .code-block-actions {
   display: flex;
   gap: 4px;
   align-items: center;
+  flex: 0 0 auto;
 }
 .code-copy-btn, .code-preview-btn {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  min-height: 28px;
   background: none;
   border: none;
   color: #999;
   cursor: pointer;
   font-size: 12px;
-  padding: 2px 8px;
+  line-height: 1;
+  padding: 4px 10px;
   border-radius: 4px;
+  touch-action: manipulation;
+  user-select: none;
+  -webkit-tap-highlight-color: transparent;
 }
 .code-copy-btn:hover, .code-preview-btn:hover { color: #fff; background: #444; }
+.code-copy-btn:focus-visible, .code-preview-btn:focus-visible {
+  outline: 2px solid rgba(255, 255, 255, 0.45);
+  outline-offset: 2px;
+}
+.code-copy-btn:disabled, .code-preview-btn:disabled {
+  cursor: default;
+  opacity: 0.72;
+}
 .code-preview-btn { border: 1px solid #555; }
 .code-block-wrapper pre {
   margin: 0;
@@ -2628,6 +2723,20 @@ html[data-divider-time='hide'] .msg-bubble .agent-message-divider span {
 .code-block-wrapper.preview-mode .code-preview-pane { display: block; }
 .code-block-wrapper.preview-mode pre { display: none; }
 
+@media (pointer: coarse) {
+  .code-block-header {
+    padding: 8px 10px;
+  }
+  .code-block-actions {
+    gap: 6px;
+  }
+  .code-copy-btn, .code-preview-btn {
+    min-width: 44px;
+    min-height: 36px;
+    padding: 0 12px;
+  }
+}
+
 /* Tool calls */
 .msg-tools {
   display: flex;
@@ -5317,7 +5426,8 @@ html[data-theme='coolvibe'] .settings-back:hover {
   box-shadow: var(--dark-shadow-soft);
 }
 
-:is(html[data-theme='carbon'], html[data-theme='nocturne'], html[data-theme='cinder']) .cross-conversation-id-btn {
+:is(html[data-theme='carbon'], html[data-theme='nocturne'], html[data-theme='cinder']) .cross-conversation-id-btn,
+:is(html[data-theme='carbon'], html[data-theme='nocturne'], html[data-theme='cinder']) .cross-conversation-collapse-btn {
   background: var(--dark-panel-soft);
   border-color: var(--border-color);
 }