fix: Android null-safety Gson crash + AgentChat full UX overhaul (Round 1-4)

Android:
- Add NullSafeStringAdapter to GsonBuilder globally to prevent null String injection into non-nullable Kotlin fields
- Add defensive null-safe mappings in AgentRepository and all UI Text() calls

Frontend AgentChat (4 rounds):
- Round 1: Stop generation button, server-side session history sync, smart scroll
- Round 2: Full markdown rendering (marked), file/image upload with drag-drop, message edit/delete
- Round 3: TTS speech (browser SpeechSynthesis), voice input (SpeechRecognition), empty state guidance, model/temperature selector
- Round 4: Extract shared chat core — useMarkdown, useFileUpload, ChatMessageBubble, ChatInputArea modules — merge AgentChat.vue and AgentChatPreview.vue divergent code

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/components/ChatInputArea.vue

@@ -0,0 +1,167 @@
+<template>
+  <div class="chat-input" :class="{ 'drag-over': dragOver }">
+    <input
+      ref="fileInputEl"
+      type="file"
+      class="hidden-file-input"
+      multiple
+      :accept="acceptTypes"
+      @change="$emit('filesSelected', $event)"
+    />
+
+    <!-- Attachment preview strip -->
+    <div v-if="attachments.length > 0" class="attach-strip">
+      <div v-for="(a, i) in attachments" :key="`att-${i}`" class="attach-item">
+        <button type="button" class="attach-remove" @click="$emit('removeAttachment', i)">×</button>
+        <img v-if="a.thumbUrl" :src="a.thumbUrl" class="attach-thumb" :alt="a.filename" />
+        <div v-else class="attach-file-icon">
+          <el-icon :size="22"><Document /></el-icon>
+        </div>
+        <div class="attach-name" :title="a.filename">{{ a.filename }}</div>
+      </div>
+    </div>
+
+    <!-- Textarea -->
+    <el-input
+      :model-value="modelValue"
+      @update:model-value="$emit('update:modelValue', $event)"
+      type="textarea"
+      :rows="3"
+      :placeholder="placeholder"
+      :disabled="disabled"
+      @keydown.enter.exact.prevent="$emit('send')"
+      @keydown.shift.enter.exact="onShiftEnter"
+    />
+
+    <!-- Footer -->
+    <div class="input-footer">
+      <span v-if="disclaimer" class="disclaimer">{{ disclaimer }}</span>
+      <div class="input-actions">
+        <!-- Attach file button -->
+        <el-button text size="small" :disabled="disabled" @click="$emit('attachFile')" title="上传文件">
+          <el-icon :size="20"><Paperclip /></el-icon>
+        </el-button>
+
+        <!-- Voice input button -->
+        <template v-if="voiceSupported">
+          <el-button v-if="!isListening" text size="small" :disabled="disabled" @click="$emit('startVoice')" title="语音输入">
+            <el-icon :size="20"><Microphone /></el-icon>
+          </el-button>
+          <el-button v-else text size="small" type="danger" @click="$emit('stopVoice')" class="recording-btn" title="停止录音">
+            <el-icon :size="20"><VideoPause /></el-icon>
+          </el-button>
+        </template>
+        <span v-if="isListening" class="recording-hint">正在聆听...</span>
+
+        <!-- Extra buttons slot -->
+        <slot name="extraActions" />
+
+        <!-- Send / Stop -->
+        <el-button v-if="showStop" type="danger" @click="$emit('stop')" class="send-btn">
+          <el-icon style="margin-right:4px"><VideoPause /></el-icon>停止
+        </el-button>
+        <el-button v-else type="primary" @click="$emit('send')" :disabled="!canSend" class="send-btn">
+          发送
+        </el-button>
+      </div>
+    </div>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { computed, ref, watchEffect } from 'vue'
+import { Paperclip, Microphone, VideoPause, Document } from '@element-plus/icons-vue'
+import type { PendingAttachment } from '@/composables/useFileUpload'
+
+const props = defineProps<{
+  modelValue: string
+  loading: boolean
+  disabled: boolean
+  attachments: PendingAttachment[]
+  dragOver: boolean
+  showStop: boolean
+  isListening: boolean
+  voiceSupported: boolean
+  placeholder?: string
+  disclaimer?: string
+  acceptTypes?: string
+}>()
+
+defineEmits<{
+  'update:modelValue': [value: string]
+  send: []
+  stop: []
+  attachFile: []
+  startVoice: []
+  stopVoice: []
+  filesSelected: [event: Event]
+  removeAttachment: [index: number]
+}>()
+
+const fileInputEl = ref<HTMLInputElement | null>(null)
+
+const canSend = computed(() => {
+  if (props.loading || props.disabled) return false
+  if (props.modelValue.trim()) return true
+  if (props.attachments.length > 0) return true
+  return false
+})
+
+// Expose fileInputEl for parent to trigger click
+defineExpose({ fileInputEl })
+
+function onShiftEnter(e: Event) {
+  // Browser's default textarea behavior handles Shift+Enter (inserts newline)
+  // This handler just prevents the @keydown.enter.exact from also firing
+}
+</script>
+
+<style scoped>
+.chat-input {
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+  padding-top: 12px;
+  border-top: 1px solid var(--el-border-color-light);
+}
+.chat-input.drag-over {
+  background: var(--el-color-primary-light-9);
+  border-radius: 8px;
+  outline: 2px dashed var(--el-color-primary);
+}
+.hidden-file-input { display: none; }
+.send-btn { min-width: 100px; }
+
+/* Attachment strip */
+.attach-strip { display: flex; gap: 8px; overflow-x: auto; padding: 4px 0; }
+.attach-item { position: relative; width: 64px; flex-shrink: 0; text-align: center; }
+.attach-remove {
+  position: absolute; top: -6px; right: -6px; width: 18px; height: 18px;
+  border: 2px solid #fff; border-radius: 50%; background: var(--el-color-danger);
+  color: #fff; font-size: 12px; line-height: 14px; cursor: pointer; z-index: 2;
+  padding: 0; display: flex; align-items: center; justify-content: center;
+}
+.attach-thumb {
+  width: 56px; height: 56px; object-fit: cover; border-radius: 6px;
+  border: 1px solid var(--el-border-color-light);
+}
+.attach-file-icon {
+  width: 56px; height: 56px; display: flex; align-items: center; justify-content: center;
+  background: var(--el-fill-color); border-radius: 6px;
+  border: 1px solid var(--el-border-color-light); color: var(--el-text-color-secondary);
+}
+.attach-name {
+  font-size: 10px; color: var(--el-text-color-secondary); margin-top: 2px;
+  overflow: hidden; text-overflow: ellipsis; white-space: nowrap; max-width: 64px;
+}
+
+/* Footer */
+.input-footer { display: flex; justify-content: space-between; align-items: center; gap: 8px; }
+.disclaimer { font-size: 12px; color: var(--el-text-color-secondary); }
+.input-actions { display: flex; gap: 8px; align-items: center; justify-content: flex-end; }
+
+/* Recording */
+.recording-btn { animation: pulse-rec 1.5s infinite; }
+.recording-hint { font-size: 13px; color: var(--el-color-danger); font-weight: 500; }
+@keyframes pulse-rec { 0%,100% { opacity: 1; } 50% { opacity: 0.5; } }
+</style>

frontend/src/components/ChatMessageBubble.vue

@@ -0,0 +1,205 @@
+<template>
+  <div class="msg-bubble" :class="[role, status === 'error' ? 'error' : '']">
+    <div class="msg-avatar">
+      <slot name="avatar">
+        <el-avatar :size="36" :icon="role === 'user' ? UserFilled : Promotion" />
+      </slot>
+    </div>
+    <div class="msg-body">
+      <!-- Extra content before bubble (tool calls, thinking trace, orchestrate result) -->
+      <slot name="extra" />
+
+      <!-- Main content -->
+      <div class="msg-text" v-html="contentHtml"></div>
+
+      <!-- Attachments -->
+      <div v-if="attachments?.length" class="msg-attachments" :class="attachmentsClass">
+        <div v-for="(a, ai) in attachments" :key="`att-${ai}`" class="msg-attachment-item">
+          <img
+            v-if="a.isImage && a.thumbUrl"
+            :src="a.thumbUrl"
+            :alt="a.filename"
+            class="msg-attachment-img"
+            @click="$emit('previewImage', a)"
+          />
+          <div v-else class="msg-attachment-file">
+            <el-icon :size="14"><Document /></el-icon>
+            <span class="msg-attachment-name">{{ a.filename }}</span>
+          </div>
+        </div>
+      </div>
+
+      <!-- Meta line -->
+      <div class="msg-meta">
+        <span class="msg-time">{{ formatTime(timestamp) }}</span>
+        <span v-if="iterations" class="msg-iterations">{{ iterations }} 步 · {{ toolCallsMade }} 次工具调用</span>
+        <span class="msg-actions">
+          <slot name="actions" />
+        </span>
+      </div>
+    </div>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { computed } from 'vue'
+import { UserFilled, Promotion, Document } from '@element-plus/icons-vue'
+import type { MessageAttachment } from '@/composables/useFileUpload'
+
+const props = defineProps<{
+  role: 'user' | 'assistant'
+  contentHtml: string
+  timestamp: number
+  status?: string
+  attachments?: MessageAttachment[]
+  iterations?: number
+  toolCallsMade?: number
+}>()
+
+defineEmits<{
+  previewImage: [attachment: MessageAttachment]
+}>()
+
+const attachmentsClass = computed(() => (props.role === 'user' ? 'is-user' : 'is-agent'))
+
+function formatTime(ts: number): string {
+  const d = new Date(ts)
+  return d.toLocaleTimeString('zh-CN', { hour: '2-digit', minute: '2-digit' })
+}
+</script>
+
+<style scoped>
+.msg-bubble {
+  display: flex;
+  gap: 12px;
+  max-width: 88%;
+}
+.msg-bubble.user {
+  align-self: flex-end;
+  flex-direction: row-reverse;
+}
+.msg-bubble.assistant {
+  align-self: flex-start;
+}
+.msg-body {
+  padding: 10px 14px;
+  border-radius: 12px;
+  background: var(--el-fill-color-light);
+  line-height: 1.6;
+  font-size: 14px;
+  min-width: 0;
+}
+.msg-bubble.user .msg-body {
+  background: var(--el-color-primary-light-8);
+}
+.msg-bubble.error .msg-body {
+  border: 1px solid var(--el-color-danger-light-5);
+}
+
+/* Content markdown styles */
+.msg-text :deep(pre) {
+  background: #1e1e2e;
+  color: #cdd6f4;
+  padding: 14px;
+  border-radius: 8px;
+  overflow-x: auto;
+  font-size: 13px;
+  line-height: 1.55;
+  margin: 8px 0;
+}
+.msg-text :deep(pre code) {
+  background: none;
+  padding: 0;
+  border-radius: 0;
+  font-size: inherit;
+  color: inherit;
+}
+.msg-text :deep(code) {
+  background: var(--el-fill-color-darker);
+  padding: 2px 6px;
+  border-radius: 4px;
+  font-size: 13px;
+  font-family: 'Cascadia Code', 'Fira Code', 'JetBrains Mono', monospace;
+}
+.msg-text :deep(h1) { font-size: 1.4em; font-weight: 700; margin: 12px 0 6px; }
+.msg-text :deep(h2) { font-size: 1.2em; font-weight: 700; margin: 10px 0 4px; }
+.msg-text :deep(h3) { font-size: 1.1em; font-weight: 600; margin: 8px 0 4px; }
+.msg-text :deep(ul), .msg-text :deep(ol) { padding-left: 20px; margin: 4px 0; }
+.msg-text :deep(li) { margin: 2px 0; }
+.msg-text :deep(blockquote) {
+  border-left: 3px solid var(--el-color-primary);
+  margin: 8px 0;
+  padding: 4px 12px;
+  color: var(--el-text-color-secondary);
+  background: var(--el-fill-color-lighter);
+  border-radius: 0 6px 6px 0;
+}
+.msg-text :deep(table) { border-collapse: collapse; width: 100%; margin: 8px 0; font-size: 13px; }
+.msg-text :deep(th), .msg-text :deep(td) { border: 1px solid var(--el-border-color); padding: 6px 10px; text-align: left; }
+.msg-text :deep(th) { background: var(--el-fill-color); font-weight: 600; }
+.msg-text :deep(a) { color: var(--el-color-primary); text-decoration: underline; }
+.msg-text :deep(hr) { border: none; border-top: 1px solid var(--el-border-color-light); margin: 12px 0; }
+.msg-text :deep(p) { margin: 4px 0; }
+.msg-text :deep(img) { max-width: 100%; border-radius: 8px; margin: 6px 0; }
+
+/* Attachments */
+.msg-attachments {
+  display: flex;
+  flex-wrap: nowrap;
+  overflow-x: auto;
+  overflow-y: hidden;
+  max-width: min(70%, 420px);
+  gap: 8px;
+  margin-top: 6px;
+  padding-bottom: 2px;
+}
+.msg-attachments.is-user { justify-content: flex-end; }
+.msg-attachments.is-agent { justify-content: flex-start; }
+.msg-attachment-item { max-width: 220px; flex: 0 0 auto; }
+.msg-attachment-img {
+  width: 120px; height: 120px;
+  object-fit: cover;
+  border-radius: 8px;
+  border: 1px solid #e4e7ed;
+  background: #fff;
+  display: block;
+  cursor: zoom-in;
+}
+.msg-attachment-file {
+  display: inline-flex;
+  align-items: center;
+  gap: 6px;
+  padding: 6px 8px;
+  border: 1px solid #e4e7ed;
+  border-radius: 8px;
+  font-size: 12px;
+  background: #fff;
+  color: #606266;
+  max-width: 220px;
+}
+.msg-attachment-name {
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+/* Meta */
+.msg-meta {
+  font-size: 11px;
+  color: var(--el-text-color-placeholder);
+  margin-top: 4px;
+  display: flex;
+  align-items: center;
+  gap: 4px;
+  flex-wrap: wrap;
+}
+.msg-iterations { color: var(--el-color-info); }
+.msg-actions {
+  margin-left: auto;
+  display: flex;
+  gap: 2px;
+  opacity: 0;
+  transition: opacity 0.15s;
+}
+.msg-body:hover .msg-actions { opacity: 1; }
+</style>

frontend/src/composables/useFileUpload.ts

@@ -0,0 +1,174 @@
+/**
+ * Shared file upload composable for chat components.
+ * Handles upload to /api/v1/uploads/preview, thumbnail generation, text preview,
+ * and drag-and-drop state management.
+ */
+import { ref } from 'vue'
+import type { Ref } from 'vue'
+import api from '@/api'
+
+export interface PendingAttachment {
+  relative_path: string
+  filename: string
+  size?: number
+  content_type?: string
+  thumbUrl?: string      // local blob URL for image thumbnails
+  previewText?: string   // local text preview for small text files
+  previewNote?: string   // human-readable note for non-text files
+}
+
+export interface MessageAttachment {
+  relative_path: string
+  filename: string
+  thumbUrl?: string
+  isImage?: boolean
+  content_type?: string
+}
+
+const TEXT_PREVIEW_EXTS = new Set([
+  'txt', 'md', 'markdown', 'csv', 'json', 'jsonl', 'log', 'yaml', 'yml',
+  'py', 'ts', 'js', 'mjs', 'cjs', 'vue', 'html', 'htm', 'xml', 'css',
+  'sql', 'sh', 'bat', 'ps1', 'ini', 'cfg', 'properties', 'rst', 'tex',
+  'gitignore', 'env',
+])
+
+const PREVIEW_MAX_FILE_BYTES = 512 * 1024
+const PREVIEW_MAX_CHARS = 12000
+
+export function useFileUpload() {
+  const pendingAttachments: Ref<PendingAttachment[]> = ref([])
+  const fileInputRef: Ref<HTMLInputElement | null> = ref(null)
+  const inputDragOver = ref(false)
+
+  function isImageFile(file: File): boolean {
+    if (file.type?.startsWith('image/')) return true
+    const ext = file.name.split('.').pop()?.toLowerCase() || ''
+    return ['png', 'jpg', 'jpeg', 'gif', 'webp', 'bmp', 'tif', 'tiff'].includes(ext)
+  }
+
+  function isValidExtForTextPreview(filename: string): boolean {
+    const m = filename.match(/\.([^.]+)$/)
+    const ext = (m?.[1] || '').toLowerCase()
+    return TEXT_PREVIEW_EXTS.has(ext)
+  }
+
+  async function readLocalTextPreview(file: File): Promise<string | undefined> {
+    if (!isValidExtForTextPreview(file.name)) return undefined
+    if (file.size > PREVIEW_MAX_FILE_BYTES) return undefined
+    return new Promise((resolve) => {
+      const r = new FileReader()
+      r.onload = () => {
+        let t = String(r.result ?? '')
+        if (t.length > PREVIEW_MAX_CHARS) {
+          t = t.slice(0, PREVIEW_MAX_CHARS) +
+            `\n\n...（仅展示前 ${PREVIEW_MAX_CHARS} 字，完整内容请发送后由助手读取文件）`
+        }
+        resolve(t)
+      }
+      r.onerror = () => resolve(undefined)
+      r.readAsText(file, 'UTF-8')
+    })
+  }
+
+  async function uploadFiles(fileList: File[]): Promise<PendingAttachment[]> {
+    const uploaded: PendingAttachment[] = []
+    for (const file of fileList) {
+      const fd = new FormData()
+      fd.append('file', file)
+      try {
+        const res = await api.post<PendingAttachment & { content_type?: string }>(
+          '/api/v1/uploads/preview', fd
+        )
+        const d = res.data as any
+        if (d?.relative_path) {
+          const previewText = await readLocalTextPreview(file)
+          let thumbUrl: string | undefined
+          if (isImageFile(file)) {
+            thumbUrl = URL.createObjectURL(file)
+          }
+          const entry: PendingAttachment = {
+            relative_path: d.relative_path,
+            filename: d.filename || file.name,
+            size: d.size || file.size,
+            content_type: d.content_type,
+            thumbUrl,
+            previewText: previewText || undefined,
+            previewNote: previewText
+              ? undefined
+              : '发送后由智能体通过 file_read 读取（支持 PDF、Word、Excel、图片 OCR 等）',
+          }
+          pendingAttachments.value.push(entry)
+          uploaded.push(entry)
+        }
+      } catch {
+        /* handled by api interceptor */
+      }
+    }
+    return uploaded
+  }
+
+  function removeAttachment(index: number) {
+    const cur = pendingAttachments.value[index]
+    if (cur?.thumbUrl) {
+      try { URL.revokeObjectURL(cur.thumbUrl) } catch { /* ignore */ }
+    }
+    pendingAttachments.value.splice(index, 1)
+  }
+
+  function clearAttachments() {
+    for (const a of pendingAttachments.value) {
+      if (a.thumbUrl) {
+        try { URL.revokeObjectURL(a.thumbUrl) } catch { /* ignore */ }
+      }
+    }
+    pendingAttachments.value = []
+  }
+
+  function buildAttachmentContext(): string {
+    if (pendingAttachments.value.length === 0) return ''
+    const lines: string[] = ['\n\n--- 附件 ---']
+    for (const a of pendingAttachments.value) {
+      lines.push(`- 文件: ${a.filename} (路径: ${a.relative_path})`)
+      if (a.previewText) {
+        const truncated = a.previewText.length > 2000
+          ? a.previewText.slice(0, 2000) + '\n...(已截断)'
+          : a.previewText
+        lines.push(`  内容预览:\n\`\`\`\n${truncated}\n\`\`\``)
+      }
+    }
+    return lines.join('\n')
+  }
+
+  function onDragLeave(e: DragEvent) {
+    const target = e.currentTarget as HTMLElement
+    if (!target.contains(e.relatedTarget as Node)) {
+      inputDragOver.value = false
+    }
+  }
+
+  async function onDrop(e: DragEvent): Promise<PendingAttachment[]> {
+    inputDragOver.value = false
+    const files = e.dataTransfer?.files
+    if (files?.length) return uploadFiles(Array.from(files))
+    return []
+  }
+
+  async function onFilesSelected(e: Event): Promise<PendingAttachment[]> {
+    const input = e.target as HTMLInputElement
+    const files = input.files
+    input.value = '' // Reset so the same file can be re-selected
+    if (files?.length) return uploadFiles(Array.from(files))
+    return []
+  }
+
+  function handleAttachFile() {
+    fileInputRef.value?.click()
+  }
+
+  return {
+    pendingAttachments, fileInputRef, inputDragOver,
+    uploadFiles, removeAttachment, clearAttachments, buildAttachmentContext,
+    onDragLeave, onDrop, onFilesSelected, handleAttachFile,
+    isImageFile,
+  }
+}

frontend/src/composables/useMarkdown.ts

@@ -0,0 +1,37 @@
+/**
+ * Shared Markdown rendering — extracts common renderMarkdown from both chat components.
+ */
+import { marked } from 'marked'
+
+let configured = false
+
+function ensureConfigured() {
+  if (configured) return
+  marked.setOptions({
+    breaks: true,
+    gfm: true,
+  })
+  configured = true
+}
+
+export function useMarkdown() {
+  ensureConfigured()
+
+  function renderMarkdown(text: string): string {
+    if (!text) return ''
+    try {
+      const raw = marked.parse(text) as string
+      // Add target="_blank" to links for safety
+      return raw.replace(/<a /g, '<a target="_blank" rel="noopener" ')
+    } catch {
+      // Fallback: escape HTML and preserve newlines
+      return text
+        .replace(/&/g, '&amp;')
+        .replace(/</g, '&lt;')
+        .replace(/>/g, '&gt;')
+        .replace(/\n/g, '<br>')
+    }
+  }
+
+  return { renderMarkdown }
+}

frontend/src/views/AgentChat.vue

@@ -21,6 +21,31 @@
               <span>{{ a.name }}</span>
             </el-option>
           </el-select>
+
+          <!-- Session selector -->
+          <el-select
+            v-model="currentSessionId"
+            placeholder="对话记录"
+            style="width: 200px"
+            :disabled="!currentAgentId"
+            @change="switchSession"
+            clearable
+          >
+            <el-option label="+ 新对话" value="__new__">
+              <span style="color: var(--el-color-primary); font-weight: 500">+ 新对话</span>
+            </el-option>
+            <el-option
+              v-for="s in sessions"
+              :key="s.session_id"
+              :label="s.title || '未命名对话'"
+              :value="s.session_id"
+            >
+              <div style="display:flex;flex-direction:column">
+                <span class="session-option-title">{{ s.title || '未命名对话' }}</span>
+                <span class="session-option-meta">{{ s.message_count }} 条消息 · {{ relativeTimeText(s.updated_at) }}</span>
+              </div>
+            </el-option>
+          </el-select>
         </template>
 
         <!-- 编排模式：模式选择 + Agent 数 -->
@@ -41,20 +66,54 @@
     </div>
 
     <div class="chat-messages" ref="messagesRef">
-      <div v-if="displayMessages.length === 0" class="chat-empty">
-        <el-icon :size="48"><ChatLineSquare /></el-icon>
-        <p v-if="chatMode === 'single'">选择一个 Agent 开始对话</p>
-        <p v-else>配置多个 Agent 后发送消息进行编排对话</p>
-        <p class="hint">Agent 可以使用内置工具帮你完成任务</p>
+      <!-- Rich empty state -->
+      <div v-if="displayMessages.length === 0 && !loading" class="chat-empty">
+        <template v-if="chatMode === 'single' && agent">
+          <el-avatar :size="56" icon="Promotion" style="background:var(--el-color-primary-light-5);margin-bottom:8px" />
+          <h3 class="welcome-title">{{ agent.name }}</h3>
+          <p v-if="agent.description" class="welcome-desc">{{ agent.description }}</p>
+          <div class="welcome-tags">
+            <el-tag size="small" type="info" v-if="agent.version">v{{ agent.version }}</el-tag>
+            <el-tag size="small" :type="agent.status === 'published' ? 'success' : 'warning'">{{ agent.status === 'published' ? '已发布' : agent.status }}</el-tag>
+          </div>
+          <p class="hint">可以问我任何问题，或者试试下面的示例：</p>
+          <div class="preset-questions">
+            <div class="preset-q" v-for="(q, qi) in getPresetQuestions()" :key="qi" @click="sendPresetQuestion(q)">
+              {{ q }}
+            </div>
+          </div>
+        </template>
+        <template v-else-if="chatMode === 'single'">
+          <el-icon :size="48"><ChatLineSquare /></el-icon>
+          <p>选择一个智能体开始对话</p>
+          <p class="hint">从上方下拉框中选择已创建的 Agent</p>
+          <div class="agent-quick-list" v-if="agents.length > 0">
+            <el-button v-for="a in agents.slice(0, 6)" :key="a.id" size="small" @click="currentAgentId = a.id; switchAgent()" style="margin:4px">
+              {{ a.name }}
+            </el-button>
+          </div>
+        </template>
+        <template v-else>
+          <el-icon :size="48"><ChatLineSquare /></el-icon>
+          <p>配置多个 Agent 后发送消息进行编排对话</p>
+          <p class="hint">支持辩论、路由、顺序、流水线四种编排模式</p>
+        </template>
       </div>
 
-      <div v-for="(msg, i) in displayMessages" :key="i" class="message" :class="[msg.role, msg.status === 'error' ? 'error' : '']">
-        <div class="message-avatar">
-          <el-avatar :size="36" :icon="msg.role === 'user' ? UserFilled : Promotion" />
-        </div>
-        <div class="message-bubble">
-          <!-- 编排模式：显示每个 Agent 的独立输出 -->
-          <div v-if="msg.orchestrateResult" class="orchestrate-result">
+      <!-- Messages using shared ChatMessageBubble -->
+      <ChatMessageBubble
+        v-for="(msg, i) in displayMessages"
+        :key="i"
+        :role="msg.role"
+        :content-html="renderMarkdown(msg.orchestrateResult?.final_answer || msg.content)"
+        :timestamp="msg.timestamp"
+        :status="msg.status"
+        :iterations="msg.iterations"
+        :tool-calls-made="msg.tool_calls_made"
+      >
+        <!-- Orchestrate result -->
+        <template v-if="msg.orchestrateResult" #extra>
+          <div class="orchestrate-result">
             <div class="orch-header">
               <el-tag size="small" type="info">{{ msg.orchestrateResult.mode }}</el-tag>
               <span class="orch-agent-count">{{ msg.orchestrateResult.steps.length }} 个 Agent</span>
@@ -85,72 +144,76 @@
               </div>
             </div>
           </div>
+        </template>
 
-          <!-- 单 Agent 模式：原有内容 -->
-          <template v-if="!msg.orchestrateResult">
-            <div class="message-text" v-html="renderMarkdown(msg.content)"></div>
-            <div v-if="msg.tool_calls && msg.tool_calls.length > 0" class="tool-calls">
-              <div class="tool-calls-header">
-                <el-icon><Tools /></el-icon> 工具调用 ({{ msg.tool_calls.length }})
-              </div>
-              <div v-for="(tc, j) in msg.tool_calls" :key="j" class="tool-call-item">
-                <span class="tool-name">{{ tc.function?.name || '?' }}</span>
-                <el-tag size="small" type="info">{{ safeParseArgCount(tc.function?.arguments) }} 个参数</el-tag>
-              </div>
+        <!-- Tool calls + thinking trace for non-orchestrate messages -->
+        <template v-if="!msg.orchestrateResult" #extra>
+          <div v-if="msg.tool_calls && msg.tool_calls.length > 0" class="tool-calls">
+            <div class="tool-calls-header">
+              <el-icon><Tools /></el-icon> 工具调用 ({{ msg.tool_calls.length }})
             </div>
+            <div v-for="(tc, j) in msg.tool_calls" :key="j" class="tool-call-item">
+              <span class="tool-name">{{ tc.function?.name || '?' }}</span>
+              <el-tag size="small" type="info">{{ safeParseArgCount(tc.function?.arguments) }} 个参数</el-tag>
+            </div>
+          </div>
 
-            <!-- 思考链 -->
-            <div v-if="msg.steps && msg.steps.length > 0" class="thinking-trace">
-              <div class="trace-header" @click="toggleTrace(msg)">
-                <el-icon><CaretRight :style="{ transform: msg._traceOpen ? 'rotate(90deg)' : '' }" /></el-icon>
-                <span>思考链 ({{ msg.steps.length }} 步)</span>
-              </div>
-              <div v-show="msg._traceOpen" class="trace-steps">
-                <div v-for="(step, si) in msg.steps" :key="si" class="trace-step" :class="'step-' + step.type">
-                  <div class="step-icon">
-                    <el-icon v-if="step.type === 'think'"><ChatDotSquare /></el-icon>
-                    <el-icon v-else-if="step.type === 'tool_result'"><Tools /></el-icon>
-                    <el-icon v-else><Select /></el-icon>
+          <div v-if="msg.steps && msg.steps.length > 0" class="thinking-trace">
+            <div class="trace-header" @click="toggleTrace(msg)">
+              <el-icon><CaretRight :style="{ transform: msg._traceOpen ? 'rotate(90deg)' : '' }" /></el-icon>
+              <span>思考链 ({{ msg.steps.length }} 步)</span>
+            </div>
+            <div v-show="msg._traceOpen" class="trace-steps">
+              <div v-for="(step, si) in msg.steps" :key="si" class="trace-step" :class="'step-' + step.type">
+                <div class="step-icon">
+                  <el-icon v-if="step.type === 'think'"><ChatDotSquare /></el-icon>
+                  <el-icon v-else-if="step.type === 'tool_result'"><Tools /></el-icon>
+                  <el-icon v-else><Select /></el-icon>
+                </div>
+                <div class="step-body">
+                  <div class="step-header">
+                    <span class="step-tag" :class="'tag-' + step.type">{{ {think:'思考',tool_result:'工具结果',final:'最终回答'}[step.type] || step.type }}</span>
+                    <span class="step-iter">#{{ step.iteration }}</span>
+                    <span v-if="step.tool_name" class="step-tool-name">{{ step.tool_name }}</span>
                   </div>
-                  <div class="step-body">
-                    <div class="step-header">
-                      <span class="step-tag" :class="'tag-' + step.type">{{ {think:'思考',tool_result:'工具结果',final:'最终回答'}[step.type] || step.type }}</span>
-                      <span class="step-iter">#{{ step.iteration }}</span>
-                      <span v-if="step.tool_name" class="step-tool-name">{{ step.tool_name }}</span>
-                    </div>
-                    <div v-if="step.content" class="step-content" v-html="renderMarkdown(step.content)"></div>
-                    <div v-if="step.reasoning" class="step-reasoning">
-                      <div class="reasoning-header">推理过程</div>
-                      <div class="reasoning-text">{{ step.reasoning }}</div>
-                    </div>
-                    <div v-if="step.tool_input && Object.keys(step.tool_input).length" class="step-tool-input">
-                      <div class="reasoning-header">参数</div>
-                      <pre>{{ JSON.stringify(step.tool_input, null, 2) }}</pre>
-                    </div>
-                    <div v-if="step.tool_result" class="step-tool-result">
-                      <div class="reasoning-header">结果</div>
-                      <pre>{{ step.tool_result }}</pre>
-                    </div>
+                  <div v-if="step.content" class="step-content" v-html="renderMarkdown(step.content)"></div>
+                  <div v-if="step.reasoning" class="step-reasoning">
+                    <div class="reasoning-header">推理过程</div>
+                    <div class="reasoning-text">{{ step.reasoning }}</div>
+                  </div>
+                  <div v-if="step.tool_input && Object.keys(step.tool_input).length" class="step-tool-input">
+                    <div class="reasoning-header">参数</div>
+                    <pre>{{ JSON.stringify(step.tool_input, null, 2) }}</pre>
+                  </div>
+                  <div v-if="step.tool_result" class="step-tool-result">
+                    <div class="reasoning-header">结果</div>
+                    <pre>{{ step.tool_result }}</pre>
                   </div>
                 </div>
               </div>
             </div>
-          </template>
-
-          <div class="message-meta">
-            {{ msg.role === 'user' ? '用户' : 'Agent' }} · {{ relativeTime(msg.timestamp) }}
-            <span v-if="msg.iterations" class="meta-iterations">· {{ msg.iterations }} 步 · {{ msg.tool_calls_made }} 次工具调用</span>
-            <span class="meta-actions">
-              <el-button v-if="msg.role === 'assistant'" link size="small" @click="copyMessage(msg)" title="复制">
-                <el-icon><DocumentCopy /></el-icon>
-              </el-button>
-              <el-button v-if="msg.status === 'error'" link type="danger" size="small" @click="retryMessage(i)" title="重试">
-                <el-icon><Refresh /></el-icon>
-              </el-button>
-            </span>
           </div>
-        </div>
-      </div>
+        </template>
+
+        <!-- Actions slot -->
+        <template #actions>
+          <el-button v-if="msg.role === 'assistant' && msg.content" link size="small" @click="isSpeaking ? stopSpeak() : speakMessage(msg.orchestrateResult?.final_answer || msg.content)" :title="isSpeaking ? '停止朗读' : '朗读'">
+            <el-icon><Headset v-if="!isSpeaking" /><VideoPause v-else /></el-icon>
+          </el-button>
+          <el-button v-if="msg.role === 'user'" link size="small" @click="editMessage(i)" title="编辑">
+            <el-icon><Edit /></el-icon>
+          </el-button>
+          <el-button v-if="msg.role === 'assistant'" link size="small" @click="copyMessage(msg)" title="复制">
+            <el-icon><DocumentCopy /></el-icon>
+          </el-button>
+          <el-button v-if="msg.status === 'error'" link type="danger" size="small" @click="retryMessage(i)" title="重试">
+            <el-icon><Refresh /></el-icon>
+          </el-button>
+          <el-button link size="small" @click="deleteMessage(i)" title="删除">
+            <el-icon style="color:var(--el-color-danger)"><Delete /></el-icon>
+          </el-button>
+        </template>
+      </ChatMessageBubble>
 
       <div v-if="loading && !streamingActive" class="message assistant">
         <div class="message-avatar"><el-avatar :size="36" icon="Promotion" /></div>
@@ -160,12 +223,49 @@
       </div>
     </div>
 
-    <div class="chat-input">
-      <el-input v-model="inputMessage" type="textarea" :rows="3" placeholder="输入你的问题..." @keydown.enter.exact.prevent="sendMessage" :disabled="loading" />
-      <el-button type="primary" @click="sendMessage" :loading="loading" :disabled="!inputMessage.trim()" class="send-btn">
-        {{ loading ? '处理中...' : '发送' }}
-      </el-button>
-    </div>
+    <!-- Shared ChatInputArea -->
+    <ChatInputArea
+      ref="inputAreaRef"
+      v-model="inputMessage"
+      :loading="loading"
+      :disabled="loading || (chatMode === 'single' && !currentAgentId)"
+      :attachments="pendingAttachments"
+      :drag-over="inputDragOver"
+      :show-stop="loading"
+      :is-listening="isListening"
+      :voice-supported="voiceSupported"
+      placeholder="输入你的问题...&#10;Enter 发送，Shift+Enter 换行&#10;支持拖拽或粘贴图片/文件"
+      @send="sendMessage"
+      @stop="stopGeneration"
+      @attach-file="handleAttachFile"
+      @start-voice="startListening"
+      @stop-voice="stopListening"
+      @files-selected="onFilesSelected"
+      @remove-attachment="removeAttachment"
+    >
+      <template #extraActions>
+        <el-popover v-if="chatMode === 'single'" placement="top" :width="260" trigger="click">
+          <template #reference>
+            <el-button text size="small" title="对话设置"><el-icon :size="18"><Setting /></el-icon></el-button>
+          </template>
+          <div class="chat-settings-popover">
+            <div style="margin-bottom:8px;font-size:13px;font-weight:500">模型</div>
+            <el-select v-model="chatModel" size="small" style="width:100%">
+              <el-option label="DeepSeek V4 Pro" value="deepseek-v4-pro" />
+              <el-option label="DeepSeek V4 Flash" value="deepseek-v4-flash" />
+              <el-option label="GPT-4o" value="gpt-4o" />
+              <el-option label="GPT-4o Mini" value="gpt-4o-mini" />
+              <el-option label="Claude Opus 4.6" value="claude-opus-4-6" />
+              <el-option label="Claude Sonnet 4.6" value="claude-sonnet-4-6" />
+            </el-select>
+            <div style="margin:10px 0 4px;font-size:13px;font-weight:500">Temperature: {{ chatTemperature.toFixed(1) }}</div>
+            <el-slider v-model="chatTemperature" :min="0" :max="2" :step="0.1" size="small" show-stops />
+            <div style="margin:10px 0 4px;font-size:13px;font-weight:500">最大迭代</div>
+            <el-input-number v-model="chatMaxIterations" :min="1" :max="50" size="small" style="width:100%" />
+          </div>
+        </el-popover>
+      </template>
+    </ChatInputArea>
 
     <!-- 编排 Agent 编辑器 -->
     <el-dialog v-model="showOrchestrateEditor" title="编排 Agent 配置" width="700px" @closed="saveState">
@@ -224,14 +324,27 @@
 </template>
 
 <script setup lang="ts">
-import { ref, computed, watch, onMounted, nextTick } from 'vue'
+import { ref, computed, watch, onMounted, onUnmounted, nextTick } from 'vue'
 import { useRoute } from 'vue-router'
 import { ElMessage } from 'element-plus'
-import { ChatLineSquare, UserFilled, Promotion, Tools, CaretRight, ChatDotSquare, Select, DocumentCopy, Refresh } from '@element-plus/icons-vue'
+import { ChatLineSquare, UserFilled, Promotion, Tools, CaretRight, ChatDotSquare, Select, DocumentCopy, Refresh, VideoPause, Edit, Delete, Headset, Setting } from '@element-plus/icons-vue'
 import MainLayout from '@/components/MainLayout.vue'
+import ChatMessageBubble from '@/components/ChatMessageBubble.vue'
+import ChatInputArea from '@/components/ChatInputArea.vue'
 import api from '@/api'
 import type { Agent } from '@/stores/agent'
+import { useMarkdown } from '@/composables/useMarkdown'
+import { useFileUpload } from '@/composables/useFileUpload'
+import { useTTS } from '@/composables/useTTS'
+import { useSpeechRecognition } from '@/composables/useSpeechRecognition'
 
+// Shared composables
+const { renderMarkdown } = useMarkdown()
+const { pendingAttachments, fileInputRef, inputDragOver, uploadFiles, removeAttachment, clearAttachments, buildAttachmentContext, onDragLeave, onDrop, onFilesSelected, handleAttachFile } = useFileUpload()
+const { isSpeaking, speak: ttsSpeak, stop: ttsStop } = useTTS()
+const { isListening, transcript, supported: voiceSupported, start: voiceStart, stop: voiceStop } = useSpeechRecognition()
+
+// TTS & Voice
 interface AgentStep {
   iteration: number; type: string; content: string
   tool_name?: string; tool_input?: Record<string, any>; tool_result?: string; reasoning?: string
@@ -257,7 +370,7 @@ interface OrchestrateAgentForm {
 const STORAGE_KEY = 'agent_chat_state'
 
 interface ChatState {
-  messages: Record<string, ChatMessage[]>  // keyed by agentId / '__bare__' / '__orchestrate__'
+  messages: Record<string, ChatMessage[]>
   sessionId: Record<string, string>
   currentAgentId: string
   chatMode: 'single' | 'orchestrate'
@@ -297,12 +410,10 @@ function loadState(): ChatState | null {
     const raw = localStorage.getItem(STORAGE_KEY)
     if (!raw) return null
     const parsed = JSON.parse(raw)
-    // TTL 过期检查：24小时后自动清除聊天记录
     if (parsed._savedAt && Date.now() - parsed._savedAt > 24 * 3600 * 1000) {
       localStorage.removeItem(STORAGE_KEY)
       return null
     }
-    // 兼容旧格式：旧版本 messages 是数组，迁移为 Record
     if (Array.isArray(parsed.messages)) {
       const oldSessionId = parsed.sessionId || ''
       parsed.messages = { '__bare__': parsed.messages }
@@ -319,15 +430,33 @@ const messages = ref<Record<string, ChatMessage[]>>({})
 const inputMessage = ref('')
 const loading = ref(false)
 const streamingActive = ref(false)
+const abortController = ref<AbortController | null>(null)
+const inputAreaRef = ref<InstanceType<typeof ChatInputArea> | null>(null)
 // 工具审批状态
 const showApprovalDialog = ref(false)
 const approvalId = ref('')
 const approvalToolName = ref('')
 const approvalArgs = ref<Record<string, any>>({})
 const messagesRef = ref<HTMLElement | null>(null)
+const isNearBottom = ref(true)
 const sessionId = ref<Record<string, string>>({})
 const agent = ref<Agent | null>(null)
 
+// 会话历史
+interface SessionInfo {
+  session_id: string; title?: string; last_message?: string
+  message_count: number; is_pinned: boolean
+  created_at?: string; updated_at?: string
+}
+const sessions = ref<SessionInfo[]>([])
+const currentSessionId = ref('')
+const sessionsLoading = ref(false)
+
+// 对话设置
+const chatModel = ref('deepseek-v4-pro')
+const chatTemperature = ref(0.8)
+const chatMaxIterations = ref(15)
+
 const currentAgentKey = computed(() => {
   if (chatMode.value === 'orchestrate') return '__orchestrate__'
   return currentAgentId.value || '__bare__'
@@ -364,6 +493,13 @@ function addOrchestrateAgent() {
 watch(chatMode, saveState)
 watch(orchestrateMode, saveState)
 
+function handleScroll() {
+  if (!messagesRef.value) return
+  const el = messagesRef.value
+  const threshold = 60
+  isNearBottom.value = (el.scrollHeight - el.scrollTop - el.clientHeight) < threshold
+}
+
 onMounted(async () => {
   await loadAgents()
 
@@ -374,7 +510,6 @@ onMounted(async () => {
     chatMode.value = saved.chatMode
     orchestrateMode.value = saved.orchestrateMode
     orchestrateAgents.value = saved.orchestrateAgents
-    // 恢复展开状态
     for (const arr of Object.values(messages.value)) {
       arr.forEach(m => { if (m.steps?.length) m._traceOpen = false })
     }
@@ -388,7 +523,14 @@ onMounted(async () => {
     await switchAgent()
   }
 
-  nextTick(scrollToBottom)
+  nextTick(() => {
+    messagesRef.value?.addEventListener('scroll', handleScroll, { passive: true })
+    scrollToBottom()
+  })
+})
+
+onUnmounted(() => {
+  messagesRef.value?.removeEventListener('scroll', handleScroll)
 })
 
 async function loadAgents() {
@@ -397,10 +539,11 @@ async function loadAgents() {
 }
 
 async function switchAgent() {
-  if (!currentAgentId.value) { agent.value = null; saveState(); nextTick(scrollToBottom); return }
+  if (!currentAgentId.value) { agent.value = null; currentSessionId.value = ''; sessions.value = []; saveState(); nextTick(scrollToBottom); return }
   try {
     const resp = await api.get(`/api/v1/agents/${currentAgentId.value}`)
     agent.value = resp.data
+    await loadSessions()
     saveState()
     nextTick(scrollToBottom)
   } catch {
@@ -409,14 +552,139 @@ async function switchAgent() {
   }
 }
 
+async function loadSessions() {
+  if (!currentAgentId.value) return
+  sessionsLoading.value = true
+  try {
+    const resp = await api.get(`/api/v1/agent-chat/${currentAgentId.value}/sessions?limit=50`)
+    sessions.value = resp.data.sessions || []
+  } catch { /* 静默失败 */ }
+  finally { sessionsLoading.value = false }
+}
+
+async function switchSession(sid: string) {
+  if (sid === '__new__') {
+    newSession()
+    return
+  }
+  currentSessionId.value = sid
+  const key = currentAgentKey.value
+  sessionId.value[key] = sid
+  sessionsLoading.value = true
+  try {
+    const resp = await api.get(`/api/v1/agent-chat/${currentAgentId.value}/sessions/${sid}/messages?limit=200`)
+    const serverMessages = resp.data.messages || []
+    messages.value[key] = serverMessages.map((m: any) => ({
+      role: m.role === 'user' ? 'user' : 'assistant',
+      content: m.content || '',
+      timestamp: m.created_at ? new Date(m.created_at).getTime() : Date.now(),
+      tool_calls: m.tool_name ? [{ function: { name: m.tool_name, arguments: m.tool_input } }] : [],
+    }))
+  } catch {
+    ElMessage.warning('加载对话历史失败')
+  }
+  finally { sessionsLoading.value = false; saveState(); nextTick(scrollToBottom) }
+}
+
+function newSession() {
+  const key = currentAgentKey.value
+  messages.value[key] = []
+  sessionId.value[key] = ''
+  currentSessionId.value = ''
+  saveState()
+  nextTick(scrollToBottom)
+}
+
+function getPresetQuestions(): string[] {
+  const name = agent.value?.name || ''
+  const desc = agent.value?.description || ''
+  const combined = `${name} ${desc}`.toLowerCase()
+  const questions: string[] = []
+  if (combined.includes('代码') || combined.includes('编程') || combined.includes('开发')) {
+    questions.push('帮我写一个 Python 脚本来处理 CSV 文件', '解释一下这段代码的作用和潜在问题', '如何设计一个 RESTful API 接口？')
+  } else if (combined.includes('写作') || combined.includes('文案') || combined.includes('文章')) {
+    questions.push('帮我写一篇关于 AI 发展的文章大纲', '润色这段文字，让它更加流畅易读', '给我几个吸引眼球的标题方案')
+  } else if (combined.includes('分析') || combined.includes('数据') || combined.includes('报告')) {
+    questions.push('分析这组数据的趋势和异常点', '帮我总结这份报告的核心要点', '对比 A 和 B 两个方案的优劣')
+  } else {
+    questions.push(`介绍一下你的能力和可以使用的工具`, '帮我分析一个复杂问题', '搜索并整理最新的相关信息')
+  }
+  return questions
+}
+
+function sendPresetQuestion(q: string) {
+  inputMessage.value = q
+  nextTick(() => sendMessage())
+}
+
+// TTS
+function speakMessage(text: string) {
+  if (!text) return
+  ttsSpeak(text)
+}
+function stopSpeak() {
+  ttsStop()
+}
+
+// Voice input
+function startListening() {
+  voiceStart('zh-CN')
+}
+function stopListening() {
+  voiceStop()
+  if (transcript.value) {
+    inputMessage.value = (inputMessage.value + ' ' + transcript.value).trim()
+    transcript.value = ''
+  }
+}
+
+watch(transcript, (val) => {
+  if (val && isListening.value) { /* display during recording */ }
+})
+
+function relativeTimeText(isoStr?: string): string {
+  if (!isoStr) return ''
+  const diff = Date.now() - new Date(isoStr).getTime()
+  if (diff < 60000) return '刚刚'
+  if (diff < 3600000) return `${Math.floor(diff / 60000)} 分钟前`
+  if (diff < 86400000) return `${Math.floor(diff / 3600000)} 小时前`
+  return `${Math.floor(diff / 86400000)} 天前`
+}
+
+// onDragLeave handled by ChatInputArea + parent wiring
+// The drag events from useFileUpload can be applied directly since ChatInputArea emits events
+function onInputDragEnter(e: DragEvent) {
+  if (loading.value || (chatMode.value === 'single' && !currentAgentId.value)) return
+  e.preventDefault()
+  if (e.dataTransfer) e.dataTransfer.dropEffect = 'copy'
+  inputDragOver.value = true
+}
+
+async function onInputDrop(e: DragEvent) {
+  inputDragOver.value = false
+  if (chatMode.value === 'single' && !currentAgentId.value) {
+    ElMessage.warning('请先选择智能体再上传文件')
+    return
+  }
+  const files = e.dataTransfer?.files
+  if (files?.length) await uploadFiles(Array.from(files))
+}
+
 async function sendMessage() {
   const text = inputMessage.value.trim()
-  if (!text || loading.value) return
+  const hasAttachments = pendingAttachments.value.length > 0
+  if (!text && !hasAttachments) return
+  if (loading.value) return
+
+  const attachCtx = buildAttachmentContext()
+  const fullText = text + attachCtx
 
   const key = currentAgentKey.value
   if (!messages.value[key]) messages.value[key] = []
-  messages.value[key].push({ role: 'user', content: text, timestamp: Date.now() })
+  messages.value[key].push({ role: 'user', content: fullText, timestamp: Date.now() })
   inputMessage.value = ''
+  pendingAttachments.value = []
+  inputDragOver.value = false
   loading.value = true
   scrollToBottom()
 
@@ -443,12 +711,12 @@ async function sendMessage() {
         ? `/api/v1/agent-chat/${currentAgentId.value}/stream`
         : '/api/v1/agent-chat/bare/stream'
 
-      // 尝试 SSE 流式（带超时控制）
       let usedStreaming = false
       let placeholderIdx = -1
       streamingActive.value = false
-      const abortController = new AbortController()
-      const streamTimeout = setTimeout(() => abortController.abort(), 300000)  // 5分钟超时，适应复杂 Agent 任务
+      abortController.value = new AbortController()
+      const streamTimeout = setTimeout(() => abortController.value?.abort(), 300000)
+
       try {
         const token = localStorage.getItem('token') || ''
         const resp = await fetch(streamEndpoint, {
@@ -457,14 +725,19 @@ async function sendMessage() {
             'Content-Type': 'application/json',
             ...(token ? { 'Authorization': `Bearer ${token}` } : {}),
           },
-          body: JSON.stringify({ message: text, session_id: sessId || undefined }),
-          signal: abortController.signal,
+          body: JSON.stringify({
+            message: text,
+            session_id: sessId || undefined,
+            model: chatModel.value || undefined,
+            temperature: chatTemperature.value,
+            max_iterations: chatMaxIterations.value,
+          }),
+          signal: abortController.value.signal,
         })
 
         if (resp.ok && resp.body) {
           usedStreaming = true
 
-          // 创建占位消息，流式更新
           const msg: ChatMessage = {
             role: 'assistant', content: '', timestamp: Date.now(),
             steps: [], _traceOpen: true, iterations: 0, tool_calls_made: 0,
@@ -498,7 +771,6 @@ async function sendMessage() {
               try {
                 const data = JSON.parse(dataStr)
 
-                // 首个事件到达 → 隐藏 loading dots，无论什么事件类型
                 if (!receivedFirstEvent) {
                   receivedFirstEvent = true
                   streamingActive.value = true
@@ -538,6 +810,10 @@ async function sendMessage() {
                   currentMsg.tool_calls_made = data.tool_calls_made || 0
                   if (data.session_id) {
                     sessionId.value[key] = data.session_id
+                    if (!currentSessionId.value) {
+                      currentSessionId.value = data.session_id
+                      loadSessions()
+                    }
                   }
                   streamingActive.value = false
                   loading.value = false
@@ -557,24 +833,31 @@ async function sendMessage() {
         }
       } catch {
         clearTimeout(streamTimeout)
-        // 流式失败时标记为非流式，让 fallback POST 兜底
         usedStreaming = false
         streamingActive.value = false
       }
 
       if (!usedStreaming) {
-        // 移除 SSE 阶段残留的占位消息（Issue #1）
         if (placeholderIdx >= 0 && placeholderIdx < messages.value[key].length) {
           messages.value[key].splice(placeholderIdx, 1)
         }
 
-        // 降级：标准 POST 请求
         const fallbackEndpoint = currentAgentId.value
           ? `/api/v1/agent-chat/${currentAgentId.value}`
           : '/api/v1/agent-chat/bare'
-        const resp = await api.post(fallbackEndpoint, { message: text, session_id: sessId || undefined })
+        const resp = await api.post(fallbackEndpoint, {
+          message: text,
+          session_id: sessId || undefined,
+          model: chatModel.value || undefined,
+          temperature: chatTemperature.value,
+          max_iterations: chatMaxIterations.value,
+        })
         const data = resp.data
         sessionId.value[key] = data.session_id
+        if (!currentSessionId.value) {
+          currentSessionId.value = data.session_id
+          loadSessions()
+        }
         messages.value[key].push({
           role: 'assistant', content: data.content, timestamp: Date.now(),
           iterations: data.iterations_used, tool_calls_made: data.tool_calls_made,
@@ -601,16 +884,23 @@ function clearChat() {
   messages.value[key] = []
   if (chatMode.value === 'single') {
     sessionId.value[key] = ''
+    currentSessionId.value = ''
   }
   saveState()
+  nextTick(scrollToBottom)
+}
+function scrollToBottom() { nextTick(() => { if (messagesRef.value && isNearBottom.value) messagesRef.value.scrollTop = messagesRef.value.scrollHeight }) }
+function stopGeneration() {
+  abortController.value?.abort()
+  loading.value = false
+  streamingActive.value = false
+  saveState()
 }
-function scrollToBottom() { nextTick(() => { if (messagesRef.value) messagesRef.value.scrollTop = messagesRef.value.scrollHeight }) }
 
 function safeParseArgCount(args?: string): number {
   if (!args) return 0
-  try {
-    return Object.keys(JSON.parse(args)).length
-  } catch { return 0 }
+  try { return Object.keys(JSON.parse(args)).length }
+  catch { return 0 }
 }
 
 function relativeTime(ts: number): string {
@@ -622,6 +912,27 @@ function relativeTime(ts: number): string {
   return `${d.getMonth() + 1}月${d.getDate()}日 ${d.getHours().toString().padStart(2, '0')}:${d.getMinutes().toString().padStart(2, '0')}`
 }
 
+function editMessage(idx: number) {
+  const key = currentAgentKey.value
+  const msgs = messages.value[key]
+  if (!msgs || !msgs[idx]) return
+  const msg = msgs[idx]
+  if (msg.role !== 'user') return
+  inputMessage.value = msg.content
+  msgs.splice(idx, 1)
+  saveState()
+  nextTick(scrollToBottom)
+}
+
+function deleteMessage(idx: number) {
+  const key = currentAgentKey.value
+  const msgs = messages.value[key]
+  if (!msgs || !msgs[idx]) return
+  msgs.splice(idx, 1)
+  saveState()
+  nextTick(scrollToBottom)
+}
+
 function copyMessage(msg: ChatMessage) {
   const text = msg.orchestrateResult?.final_answer || msg.content
   if (!text) return
@@ -637,7 +948,6 @@ function retryMessage(idx: number) {
   const msgs = messages.value[key]
   if (!msgs) return
 
-  // 查找错误消息之前的最后一条用户消息
   let userMsg = ''
   let userIdx = -1
   for (let i = idx - 1; i >= 0; i--) {
@@ -652,38 +962,23 @@ function retryMessage(idx: number) {
     return
   }
 
-  // 收集需要移除的消息：用户消息 + 错误消息 + 中间的流式占位消息
   const removeIndices: number[] = [userIdx, idx]
   for (let i = userIdx + 1; i < idx; i++) {
     const m = msgs[i]
-    // 流式占位消息：assistant 角色，内容为空或有 steps 但无实质内容
     if (m.role === 'assistant' && (!m.content || m.content === '') && (m.steps?.length || 0) > 0) {
       removeIndices.push(i)
     }
   }
 
-  // 从后往前删除，避免 index 错乱
   removeIndices.sort((a, b) => b - a)
   for (const ri of removeIndices) {
     msgs.splice(ri, 1)
   }
 
   saveState()
-  // 填入输入框并发送
   inputMessage.value = userMsg
   nextTick(() => sendMessage())
 }
-
-function renderMarkdown(text: string): string {
-  if (!text) return ''
-  // XSS 防护: 先转义 HTML 特殊字符，再对安全模式做 Markdown 渲染
-  return text
-    .replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;')
-    .replace(/```(\w*)\n([\s\S]*?)```/g, '<pre><code class="language-$1">$2</code></pre>')
-    .replace(/`([^`]+)`/g, '<code>$1</code>')
-    .replace(/\*\*([^*]+)\*\*/g, '<strong>$1</strong>')
-    .replace(/\n/g, '<br>')
-}
 </script>
 
 <style scoped>
@@ -693,26 +988,46 @@ function renderMarkdown(text: string): string {
 .page-header-left h3 { margin: 0; font-size: 16px; font-weight: 600; }
 .page-header-actions { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
 .chat-messages { flex: 1; overflow-y: auto; padding: 8px 0; display: flex; flex-direction: column; gap: 12px; min-height: 0; }
-.chat-empty { display: flex; flex-direction: column; align-items: center; justify-content: center; height: 100%; color: var(--el-text-color-secondary); gap: 12px; }
-.chat-empty .hint { font-size: 13px; color: var(--el-text-color-placeholder); }
+.chat-empty { display: flex; flex-direction: column; align-items: center; justify-content: center; height: 100%; color: var(--el-text-color-secondary); gap: 12px; padding: 40px 20px; text-align: center; }
+.chat-empty .hint { font-size: 13px; color: var(--el-text-color-placeholder); margin-top: 8px; }
+.welcome-title { margin: 0; font-size: 18px; font-weight: 600; color: var(--el-text-color-primary); }
+.welcome-desc { margin: 0; font-size: 14px; color: var(--el-text-color-secondary); max-width: 480px; line-height: 1.6; }
+.welcome-tags { display: flex; gap: 6px; }
+.preset-questions { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; max-width: 520px; margin-top: 4px; }
+.preset-q { padding: 8px 16px; background: var(--el-fill-color); border: 1px solid var(--el-border-color-light); border-radius: 20px; font-size: 13px; cursor: pointer; transition: all 0.15s; color: var(--el-text-color-regular); }
+.preset-q:hover { background: var(--el-color-primary-light-9); border-color: var(--el-color-primary-light-5); color: var(--el-color-primary); }
+.agent-quick-list { display: flex; flex-wrap: wrap; gap: 4px; justify-content: center; max-width: 480px; }
+
+/* Chat settings popover */
+.chat-settings-popover { padding: 4px 0; }
 .message { display: flex; gap: 12px; max-width: 88%; }
 .message.user { align-self: flex-end; flex-direction: row-reverse; }
 .message.assistant { align-self: flex-start; }
 .message-bubble { padding: 10px 14px; border-radius: 12px; background: var(--el-fill-color-light); line-height: 1.6; font-size: 14px; }
 .message.user .message-bubble { background: var(--el-color-primary-light-8); }
 .message.error .message-bubble { border: 1px solid var(--el-color-danger-light-5); }
-.message-text :deep(pre) { background: var(--el-fill-color); padding: 12px; border-radius: 8px; overflow-x: auto; font-size: 13px; }
-.message-text :deep(code) { background: var(--el-fill-color); padding: 2px 6px; border-radius: 4px; font-size: 13px; }
+.message-text :deep(pre) { background: #1e1e2e; color: #cdd6f4; padding: 14px; border-radius: 8px; overflow-x: auto; font-size: 13px; line-height: 1.55; margin: 8px 0; }
+.message-text :deep(pre code) { background: none; padding: 0; border-radius: 0; font-size: inherit; color: inherit; }
+.message-text :deep(code) { background: var(--el-fill-color-darker); padding: 2px 6px; border-radius: 4px; font-size: 13px; font-family: 'Cascadia Code', 'Fira Code', 'JetBrains Mono', monospace; }
+.message-text :deep(h1) { font-size: 1.4em; font-weight: 700; margin: 12px 0 6px; }
+.message-text :deep(h2) { font-size: 1.2em; font-weight: 700; margin: 10px 0 4px; }
+.message-text :deep(h3) { font-size: 1.1em; font-weight: 600; margin: 8px 0 4px; }
+.message-text :deep(ul), .message-text :deep(ol) { padding-left: 20px; margin: 4px 0; }
+.message-text :deep(li) { margin: 2px 0; }
+.message-text :deep(blockquote) { border-left: 3px solid var(--el-color-primary); margin: 8px 0; padding: 4px 12px; color: var(--el-text-color-secondary); background: var(--el-fill-color-lighter); border-radius: 0 6px 6px 0; }
+.message-text :deep(table) { border-collapse: collapse; width: 100%; margin: 8px 0; font-size: 13px; }
+.message-text :deep(th), .message-text :deep(td) { border: 1px solid var(--el-border-color); padding: 6px 10px; text-align: left; }
+.message-text :deep(th) { background: var(--el-fill-color); font-weight: 600; }
+.message-text :deep(a) { color: var(--el-color-primary); text-decoration: underline; }
+.message-text :deep(hr) { border: none; border-top: 1px solid var(--el-border-color-light); margin: 12px 0; }
+.message-text :deep(p) { margin: 4px 0; }
+.message-text :deep(img) { max-width: 100%; border-radius: 8px; margin: 6px 0; }
 
 /* Tool calls */
 .tool-calls { margin-top: 8px; padding-top: 8px; border-top: 1px dashed var(--el-border-color-light); }
 .tool-calls-header { display: flex; align-items: center; gap: 4px; font-size: 12px; color: var(--el-text-color-secondary); margin-bottom: 4px; }
 .tool-call-item { display: flex; align-items: center; gap: 8px; padding: 4px 8px; font-size: 12px; }
 .tool-name { font-weight: 500; color: var(--el-color-primary); }
-.message-meta { font-size: 11px; color: var(--el-text-color-placeholder); margin-top: 4px; display: flex; align-items: center; gap: 4px; flex-wrap: wrap; }
-.meta-iterations { color: var(--el-color-info); }
-.meta-actions { margin-left: auto; display: flex; gap: 2px; opacity: 0; transition: opacity 0.15s; }
-.message-bubble:hover .meta-actions { opacity: 1; }
 
 /* Thinking trace */
 .thinking-trace { margin-top: 10px; border-top: 1px solid var(--el-border-color-light); padding-top: 8px; }
@@ -745,10 +1060,9 @@ function renderMarkdown(text: string): string {
 .dot:nth-child(3) { animation-delay: 0.32s; }
 @keyframes bounce { 0%,80%,100% { transform: scale(0); } 40% { transform: scale(1); } }
 
-/* Chat input */
-.chat-input { display: flex; gap: 12px; padding-top: 12px; border-top: 1px solid var(--el-border-color-light); }
-.chat-input .el-textarea { flex: 1; }
-.send-btn { align-self: flex-end; min-width: 100px; }
+/* Session selector */
+.session-option-title { font-size: 13px; line-height: 1.4; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; max-width: 260px; }
+.session-option-meta { font-size: 11px; color: var(--el-text-color-placeholder); }
 
 /* Orchestrate result */
 .orchestrate-result { font-size: 14px; }