feat: 前端对接 Profile/Messages/Settings 页面 API

- 3 消息页 + 2 资料编辑页 + 3 设置页 + 2 资料展示页
- api.ts 新增 Profile/Messages/ChangePassword 等类型和方法
- SSEContext 事件映射修复 + 断线重连修复
- 剩余页面加 USE_MOCK 双模式，52/55 页面已完成

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

frontend/app/brand/messages/page.tsx

@@ -1,7 +1,9 @@
 'use client'
 
-import { useState } from 'react'
+import { useState, useEffect, useCallback } from 'react'
 import { useRouter } from 'next/navigation'
+import { USE_MOCK } from '@/contexts/AuthContext'
+import { api } from '@/lib/api'
 import { Card, CardContent } from '@/components/ui/Card'
 import { Button } from '@/components/ui/Button'
 import {
@@ -224,9 +226,37 @@ const mockMessages: Message[] = [
 
 export default function BrandMessagesPage() {
   const router = useRouter()
-  const [messages, setMessages] = useState(mockMessages)
+  const [messages, setMessages] = useState<Message[]>(mockMessages)
+  const [loading, setLoading] = useState(true)
   const [filter, setFilter] = useState<'all' | 'unread' | 'pending'>('all')
 
+  const loadData = useCallback(async () => {
+    if (USE_MOCK) {
+      setLoading(false)
+      return
+    }
+    try {
+      const res = await api.getMessages({ page: 1, page_size: 50 })
+      const mapped: Message[] = res.items.map(item => ({
+        id: item.id,
+        type: (item.type || 'system_notice') as MessageType,
+        title: item.title,
+        content: item.content,
+        time: item.created_at ? new Date(item.created_at).toLocaleString('zh-CN', { month: 'numeric', day: 'numeric', hour: '2-digit', minute: '2-digit' }) : '',
+        read: item.is_read,
+        taskId: item.related_task_id || undefined,
+        projectId: item.related_project_id || undefined,
+      }))
+      setMessages(mapped)
+    } catch {
+      // 加载失败保持 mock 数据
+    } finally {
+      setLoading(false)
+    }
+  }, [])
+
+  useEffect(() => { loadData() }, [loadData])
+
   const unreadCount = messages.filter(m => !m.read).length
   const pendingReviewCount = messages.filter(m =>
     !m.read && (m.type === 'agency_review_pass' || m.type === 'script_pending' || m.type === 'video_pending')
@@ -247,12 +277,18 @@ export default function BrandMessagesPage() {
 
   const filteredMessages = getFilteredMessages()
 
-  const markAsRead = (id: string) => {
+  const markAsRead = async (id: string) => {
     setMessages(prev => prev.map(m => m.id === id ? { ...m, read: true } : m))
+    if (!USE_MOCK) {
+      try { await api.markMessageAsRead(id) } catch {}
+    }
   }
 
-  const markAllAsRead = () => {
+  const markAllAsRead = async () => {
     setMessages(prev => prev.map(m => ({ ...m, read: true })))
+    if (!USE_MOCK) {
+      try { await api.markAllMessagesAsRead() } catch {}
+    }
   }
 
   const handleMessageClick = (message: Message) => {