fix(ai): AI 对话全链路修复 + 菜单配置 + 会话消息持久化

- 修复 ai_tenant_config Entity 表名错误（复数→单数）导致 budget_status 500
- 修复 ai_usage 表 SQL 引用不存在的 deleted_at 列
- 修复 risk_service SQL 列名/表名与实际数据库 schema 不匹配
- chat_handler provider 选择改为配置优先（default_provider→fallback chain）
- 新增 Ollama 非 FC provider 的 generate() 降级路径
- 新增 GET /ai/chat/sessions/{id}/messages 端点
- 前端 ChatPage 切换会话时从后端加载历史消息
- AiConfigPage 新增 default_provider 和 system_prompt 配置字段
- 迁移 000155-000156：AI 菜单调整 + AI 客服菜单 + 角色绑定
- 配额检查错误处理区分配额耗尽和 DB 异常

apps/web/src/pages/ai/ChatPage.tsx

@@ -91,9 +91,35 @@ export default function ChatPage() {
     }
   };
 
-  const handleSelectSession = (id: string) => {
+  const handleSelectSession = async (id: string) => {
     setActiveId(id);
     setMessages([]);
+    try {
+      const msgs = await aiChatApi.getSessionMessages(id);
+      const loaded: ChatMessage[] = msgs
+        .filter((m) => m.content)
+        .map((m) => ({
+          id: m.id,
+          role: m.role as 'user' | 'assistant',
+          content: m.content ?? '',
+        }));
+      if (loaded.length === 0) {
+        loaded.push({
+          id: 'welcome',
+          role: 'assistant',
+          content: '你好！我是 AI 健康助手。有什么可以帮你的？',
+        });
+      }
+      setMessages(loaded);
+    } catch {
+      setMessages([
+        {
+          id: 'welcome',
+          role: 'assistant',
+          content: '你好！我是 AI 健康助手。有什么可以帮你的？',
+        },
+      ]);
+    }
   };
 
   const handleSend = async () => {

apps/web/src/pages/health/AiConfigPage.tsx

@@ -10,13 +10,24 @@ import {
   Divider,
   Spin,
   Tabs,
+  Select,
+  Switch,
+  Collapse,
+  Typography,
 } from 'antd';
 import { SaveOutlined, UndoOutlined } from '@ant-design/icons';
-import { aiConfigApi, type AiConfig } from '../../api/ai/config';
+import { aiConfigApi, type AiConfig, type AiProviderConfig } from '../../api/ai/config';
 import { AuthButton } from '../../components/AuthButton';
 import { useThemeMode } from '../../hooks/useThemeMode';
 
 const { TextArea } = Input;
+const { Text } = Typography;
+
+const PROVIDER_LABELS: Record<string, string> = {
+  claude: 'Claude (Anthropic)',
+  openai: 'OpenAI 兼容',
+  ollama: 'Ollama (本地)',
+};
 
 export default function AiConfigPage() {
   const [config, setConfig] = useState<AiConfig | null>(null);
@@ -39,6 +50,9 @@ export default function AiConfigPage() {
         analysisModel: data.analysis_defaults.model,
         analysisTemperature: data.analysis_defaults.temperature,
         analysisMaxTokens: data.analysis_defaults.max_tokens,
+        defaultProvider: data.default_provider || 'claude',
+        // Provider fields
+        ...buildProviderFields(data.providers),
       });
     } catch {
       message.error('加载 AI 配置失败');
@@ -56,6 +70,17 @@ export default function AiConfigPage() {
       const values = await form.validateFields();
       setSaving(true);
 
+      const providers: Record<string, AiProviderConfig> = {};
+      for (const name of ['claude', 'openai', 'ollama']) {
+        providers[name] = {
+          provider_type: name,
+          enabled: values[`provider_${name}_enabled`] ?? false,
+          base_url: values[`provider_${name}_base_url`] ?? '',
+          api_key: values[`provider_${name}_api_key`] ?? '',
+          model: values[`provider_${name}_model`] ?? '',
+        };
+      }
+
       const updated: AiConfig = {
         agent: {
           model: values.agentModel,
@@ -69,6 +94,8 @@ export default function AiConfigPage() {
           temperature: values.analysisTemperature,
           max_tokens: values.analysisMaxTokens,
         },
+        default_provider: values.defaultProvider || 'claude',
+        providers,
       };
 
       const result = await aiConfigApi.update(updated);
@@ -125,6 +152,7 @@ export default function AiConfigPage() {
             {
               key: 'agent',
               label: 'Agent 对话配置',
+              forceRender: true,
               children: (
                 <Card
                   title="AI 客服 Agent 参数"
@@ -204,6 +232,7 @@ export default function AiConfigPage() {
             {
               key: 'analysis',
               label: '分析任务默认配置',
+              forceRender: true,
               children: (
                 <Card
                   title="AI 分析任务默认参数"
@@ -255,6 +284,93 @@ export default function AiConfigPage() {
                 </Card>
               ),
             },
+            {
+              key: 'providers',
+              label: '模型供应商配置',
+              forceRender: true,
+              children: (
+                <Card
+                  title="AI 模型供应商"
+                  size="small"
+                  style={cardStyle}
+                  extra="配置各 AI 供应商的连接参数，保存后立即生效"
+                >
+                  <Form.Item
+                    label="默认供应商"
+                    name="defaultProvider"
+                    extra="系统优先使用的 AI 供应商"
+                  >
+                    <Select style={{ width: 240 }}>
+                      <Select.Option value="claude">Claude (Anthropic)</Select.Option>
+                      <Select.Option value="openai">OpenAI 兼容</Select.Option>
+                      <Select.Option value="ollama">Ollama (本地)</Select.Option>
+                    </Select>
+                  </Form.Item>
+
+                  <Divider style={{ margin: '8px 0 16px' }} />
+
+                  <Collapse
+                    items={(['claude', 'openai', 'ollama'] as const).map((name) => ({
+                      key: name,
+                      forceRender: true,
+                      label: (
+                        <Space>
+                          <Form.Item
+                            name={`provider_${name}_enabled`}
+                            valuePropName="checked"
+                            noStyle
+                          >
+                            <Switch size="small" />
+                          </Form.Item>
+                          <span>{PROVIDER_LABELS[name]}</span>
+                          {config?.providers?.[name]?.enabled && (
+                            <Text type="success">已启用</Text>
+                          )}
+                        </Space>
+                      ),
+                      children: (
+                        <>
+                          <Form.Item
+                            label="Base URL"
+                            name={`provider_${name}_base_url`}
+                          >
+                            <Input placeholder={
+                              name === 'claude' ? 'https://api.anthropic.com' :
+                              name === 'openai' ? 'https://api.openai.com' :
+                              'http://localhost:11434'
+                            } />
+                          </Form.Item>
+
+                          {name !== 'ollama' && (
+                            <Form.Item
+                              label="API Key"
+                              name={`provider_${name}_api_key`}
+                              extra="已保存的 Key 会显示为掩码格式（****xxxx），输入新值即可覆盖"
+                            >
+                              <Input.Password
+                                placeholder="sk-..."
+                                visibilityToggle
+                              />
+                            </Form.Item>
+                          )}
+
+                          <Form.Item
+                            label="默认模型"
+                            name={`provider_${name}_model`}
+                          >
+                            <Input placeholder={
+                              name === 'claude' ? 'claude-sonnet-4-6' :
+                              name === 'openai' ? 'gpt-4o' :
+                              'qwen3:8b'
+                            } />
+                          </Form.Item>
+                        </>
+                      ),
+                    }))}
+                  />
+                </Card>
+              ),
+            },
           ]}
         />
 
@@ -263,14 +379,15 @@ export default function AiConfigPage() {
             <Button icon={<UndoOutlined />} onClick={handleReset}>
               恢复默认值
             </Button>
-            <AuthButton
-              permission="ai.config.manage"
-              type="primary"
-              icon={<SaveOutlined />}
-              loading={saving}
-              onClick={handleSave}
-            >
-              保存配置
+            <AuthButton code="ai.config.manage">
+              <Button
+                type="primary"
+                icon={<SaveOutlined />}
+                loading={saving}
+                onClick={handleSave}
+              >
+                保存配置
+              </Button>
             </AuthButton>
           </Space>
         </div>
@@ -278,3 +395,24 @@ export default function AiConfigPage() {
     </div>
   );
 }
+
+const PROVIDER_DEFAULTS: Record<string, { base_url: string; model: string }> = {
+  claude: { base_url: 'https://api.anthropic.com', model: 'claude-sonnet-4-6' },
+  openai: { base_url: 'https://api.openai.com', model: 'gpt-4o' },
+  ollama: { base_url: 'http://localhost:11434', model: 'qwen3:8b' },
+};
+
+function buildProviderFields(
+  providers: Record<string, AiProviderConfig> | undefined,
+): Record<string, unknown> {
+  if (!providers) return {};
+  const fields: Record<string, unknown> = {};
+  for (const [name, cfg] of Object.entries(providers)) {
+    const defaults = PROVIDER_DEFAULTS[name];
+    fields[`provider_${name}_enabled`] = cfg.enabled;
+    fields[`provider_${name}_base_url`] = cfg.base_url || defaults?.base_url || '';
+    fields[`provider_${name}_api_key`] = cfg.api_key;
+    fields[`provider_${name}_model`] = cfg.model || defaults?.model || '';
+  }
+  return fields;
+}