feat(web): Phase 2A-1 AI 侧边栏骨架 — 浮动按钮 + 聊天 Drawer

新增 Web 管理后台 AI 侧边栏：
- 右下角渐变色浮动按钮（RobotOutlined），hover 放大效果
- AiSidebar Drawer 组件：聊天消息列表 + 输入框 + 发送按钮
- 自动检测当前页面患者 ID，携带 patient_id 上下文到 /ai/chat
- 权限检查：无 ai.chat.send 权限时禁用输入并提示
- 气泡样式对话：用户消息蓝色右对齐，助手消息灰色左对齐
- 清空对话、加载态（思考中 Spin）、Enter 发送 + Shift+Enter 换行

新增文件：
- apps/web/src/api/ai/chat.ts — AI 聊天 API 模块
- apps/web/src/components/ai/AiSidebar.tsx — 侧边栏组件

修改文件：
- apps/web/src/layouts/MainLayout.tsx — 集成浮动按钮 + AiSidebar

apps/web/src/api/ai/chat.ts

@@ -0,0 +1,27 @@
+import client from '../client';
+
+export interface ChatHistoryItem {
+  role: 'user' | 'assistant';
+  content: string;
+}
+
+export interface ChatResponse {
+  reply: string;
+  message_id: string;
+  iterations: number;
+}
+
+export const aiChatApi = {
+  sendMessage: async (
+    message: string,
+    history: ChatHistoryItem[],
+    patientId?: string
+  ): Promise<ChatResponse> => {
+    const resp = await client.post('/ai/chat', {
+      message,
+      history,
+      ...(patientId ? { patient_id: patientId } : {}),
+    });
+    return resp.data.data as ChatResponse;
+  },
+};

apps/web/src/components/ai/AiSidebar.tsx

@@ -0,0 +1,255 @@
+import { useState, useRef, useEffect, useCallback } from 'react';
+import { Drawer, Input, Button, Space, Typography, Spin, Tag, theme } from 'antd';
+import { SendOutlined, RobotOutlined, DeleteOutlined } from '@ant-design/icons';
+import { useLocation } from 'react-router-dom';
+import { aiChatApi, type ChatHistoryItem } from '../../api/ai/chat';
+import { useAuthStore } from '../../stores/auth';
+
+const { Text } = Typography;
+const { TextArea } = Input;
+
+interface ChatMessage {
+  id: string;
+  role: 'user' | 'assistant';
+  content: string;
+}
+
+function extractPatientId(pathname: string): string | null {
+  const match = pathname.match(/\/health\/patients\/([0-9a-f-]+)/i);
+  return match?.[1] ?? null;
+}
+
+export default function AiSidebar({
+  open,
+  onClose,
+}: {
+  open: boolean;
+  onClose: () => void;
+}) {
+  const [messages, setMessages] = useState<ChatMessage[]>([]);
+  const [input, setInput] = useState('');
+  const [loading, setLoading] = useState(false);
+  const messagesEndRef = useRef<HTMLDivElement>(null);
+  const location = useLocation();
+  const { token } = theme.useToken();
+
+  const patientId = extractPatientId(location.pathname);
+  const permissions = useAuthStore((s) => s.permissions);
+  const canChat = permissions.includes('ai.chat.send');
+
+  // 欢迎消息
+  useEffect(() => {
+    if (open && messages.length === 0) {
+      setMessages([
+        {
+          id: 'welcome',
+          role: 'assistant',
+          content: patientId
+            ? '你好！我是 AI 健康助手。当前已关联患者档案，你可以问我关于该患者的体征、化验报告、用药等信息。'
+            : '你好！我是 AI 健康助手。你可以向我咨询健康相关问题，或打开患者详情页查看患者数据。',
+        },
+      ]);
+    }
+  }, [open]); // eslint-disable-line react-hooks/exhaustive-deps
+
+  const scrollToBottom = useCallback(() => {
+    setTimeout(() => {
+      messagesEndRef.current?.scrollIntoView({ behavior: 'smooth' });
+    }, 100);
+  }, []);
+
+  useEffect(() => {
+    scrollToBottom();
+  }, [messages, scrollToBottom]);
+
+  const handleSend = async () => {
+    const text = input.trim();
+    if (!text || loading || !canChat) return;
+
+    const userMsg: ChatMessage = {
+      id: `u-${Date.now()}`,
+      role: 'user',
+      content: text,
+    };
+
+    const newMessages = [...messages, userMsg];
+    setMessages(newMessages);
+    setInput('');
+    setLoading(true);
+
+    try {
+      const history: ChatHistoryItem[] = newMessages
+        .filter((m) => m.id !== 'welcome')
+        .map((m) => ({
+          role: m.role,
+          content: m.content,
+        }));
+
+      const resp = await aiChatApi.sendMessage(text, history, patientId ?? undefined);
+
+      setMessages((prev) => [
+        ...prev,
+        {
+          id: resp.message_id,
+          role: 'assistant',
+          content: resp.reply,
+        },
+      ]);
+    } catch {
+      setMessages((prev) => [
+        ...prev,
+        {
+          id: `err-${Date.now()}`,
+          role: 'assistant',
+          content: '抱歉，AI 服务暂时不可用，请稍后再试。',
+        },
+      ]);
+    } finally {
+      setLoading(false);
+    }
+  };
+
+  const handleKeyDown = (e: React.KeyboardEvent) => {
+    if (e.key === 'Enter' && !e.shiftKey) {
+      e.preventDefault();
+      handleSend();
+    }
+  };
+
+  const handleClear = () => {
+    setMessages([
+      {
+        id: 'welcome',
+        role: 'assistant',
+        content: '对话已清空。有什么可以帮你的？',
+      },
+    ]);
+  };
+
+  return (
+    <Drawer
+      title={
+        <Space>
+          <RobotOutlined style={{ color: token.colorPrimary }} />
+          <span>AI 健康助手</span>
+          {patientId && (
+            <Tag color="blue" style={{ marginLeft: 8, fontSize: 11 }}>
+              已关联患者
+            </Tag>
+          )}
+        </Space>
+      }
+      placement="right"
+      width={400}
+      open={open}
+      onClose={onClose}
+      styles={{
+        body: { display: 'flex', flexDirection: 'column', padding: 0 },
+      }}
+      extra={
+        <Button
+          size="small"
+          icon={<DeleteOutlined />}
+          onClick={handleClear}
+          title="清空对话"
+        />
+      }
+    >
+      {/* 消息列表 */}
+      <div
+        style={{
+          flex: 1,
+          overflowY: 'auto',
+          padding: '12px 16px',
+          background: token.colorBgLayout,
+        }}
+      >
+        {messages.map((msg) => (
+          <div
+            key={msg.id}
+            style={{
+              display: 'flex',
+              justifyContent: msg.role === 'user' ? 'flex-end' : 'flex-start',
+              marginBottom: 12,
+            }}
+          >
+            <div
+              style={{
+                maxWidth: '85%',
+                padding: '8px 12px',
+                borderRadius: 12,
+                fontSize: 14,
+                lineHeight: 1.6,
+                whiteSpace: 'pre-wrap',
+                wordBreak: 'break-word',
+                background:
+                  msg.role === 'user'
+                    ? token.colorPrimary
+                    : token.colorBgContainer,
+                color:
+                  msg.role === 'user'
+                    ? token.colorTextLightSolid
+                    : token.colorText,
+                borderBottomRightRadius: msg.role === 'user' ? 4 : 12,
+                borderBottomLeftRadius: msg.role === 'assistant' ? 4 : 12,
+              }}
+            >
+              {msg.content}
+            </div>
+          </div>
+        ))}
+        {loading && (
+          <div style={{ display: 'flex', justifyContent: 'flex-start', marginBottom: 12 }}>
+            <div
+              style={{
+                padding: '8px 16px',
+                borderRadius: 12,
+                borderBottomLeftRadius: 4,
+                background: token.colorBgContainer,
+              }}
+            >
+              <Spin size="small" /> <Text type="secondary">思考中...</Text>
+            </div>
+          </div>
+        )}
+        <div ref={messagesEndRef} />
+      </div>
+
+      {/* 输入区域 */}
+      <div
+        style={{
+          padding: 12,
+          borderTop: `1px solid ${token.colorBorderSecondary}`,
+          background: token.colorBgContainer,
+        }}
+      >
+        <Space.Compact style={{ width: '100%' }}>
+          <TextArea
+            value={input}
+            onChange={(e) => setInput(e.target.value)}
+            onKeyDown={handleKeyDown}
+            placeholder={
+              canChat ? '输入消息... (Enter 发送, Shift+Enter 换行)' : '无 AI 聊天权限'
+            }
+            disabled={loading || !canChat}
+            autoSize={{ minRows: 1, maxRows: 4 }}
+            style={{ borderRadius: '8px 0 0 8px' }}
+          />
+          <Button
+            type="primary"
+            icon={<SendOutlined />}
+            onClick={handleSend}
+            loading={loading}
+            disabled={!input.trim() || !canChat}
+            style={{ height: 'auto', borderRadius: '0 8px 8px 0', minHeight: 40 }}
+          />
+        </Space.Compact>
+        {!canChat && (
+          <Text type="warning" style={{ fontSize: 12, marginTop: 4, display: 'block' }}>
+            你没有 AI 聊天权限，请联系管理员开通。
+          </Text>
+        )}
+      </div>
+    </Drawer>
+  );
+}

apps/web/src/layouts/MainLayout.tsx

@@ -8,6 +8,7 @@ import {
   AppstoreOutlined,
   RightOutlined,
   UserOutlined,
+  RobotOutlined,
 } from '@ant-design/icons';
 import { useNavigate, useLocation } from 'react-router-dom';
 import { useAppStore } from '../stores/app';
@@ -18,6 +19,7 @@ import { getMenusForUser, type MenuInfo } from '../api/menus';
 import { getIcon } from '../utils/iconRegistry';
 import NotificationPanel from '../components/NotificationPanel';
 import ThemeSwitcher from '../components/ThemeSwitcher';
+import AiSidebar from '../components/ai/AiSidebar';
 
 const { Header, Sider, Content, Footer } = Layout;
 
@@ -311,6 +313,7 @@ export default function MainLayout({ children }: { children: React.ReactNode })
   // 动态菜单状态
   const [dynamicMenus, setDynamicMenus] = useState<MenuInfo[]>([]);
   const [menuLoading, setMenuLoading] = useState(true);
+  const [aiSidebarOpen, setAiSidebarOpen] = useState(false);
 
   useEffect(() => {
     let cancelled = false;
@@ -504,6 +507,40 @@ export default function MainLayout({ children }: { children: React.ReactNode })
           {themeConfig?.brand_copyright || 'HMS 健康管理平台'}
         </Footer>
       </Layout>
+
+      {/* AI 助手浮动按钮 + 侧边栏 */}
+      <Tooltip title="AI 健康助手" placement="left">
+        <div
+          onClick={() => setAiSidebarOpen(true)}
+          style={{
+            position: 'fixed',
+            right: 24,
+            bottom: 32,
+            width: 48,
+            height: 48,
+            borderRadius: '50%',
+            background: 'linear-gradient(135deg, #1677ff 0%, #722ed1 100%)',
+            display: 'flex',
+            alignItems: 'center',
+            justifyContent: 'center',
+            cursor: 'pointer',
+            boxShadow: '0 4px 12px rgba(22, 119, 255, 0.4)',
+            zIndex: 1000,
+            transition: 'transform 0.2s, box-shadow 0.2s',
+          }}
+          onMouseEnter={(e) => {
+            e.currentTarget.style.transform = 'scale(1.1)';
+            e.currentTarget.style.boxShadow = '0 6px 16px rgba(22, 119, 255, 0.6)';
+          }}
+          onMouseLeave={(e) => {
+            e.currentTarget.style.transform = 'scale(1)';
+            e.currentTarget.style.boxShadow = '0 4px 12px rgba(22, 119, 255, 0.4)';
+          }}
+        >
+          <RobotOutlined style={{ color: '#fff', fontSize: 22 }} />
+        </div>
+      </Tooltip>
+      <AiSidebar open={aiSidebarOpen} onClose={() => setAiSidebarOpen(false)} />
     </Layout>
   );
 }