feat: AI 助手模型管理（CRUD、会话绑定、自动化验收）

- Flyway V6：模型表、默认种子、ai_chat_session.model_id 回填
- 管理端 /api/admin/ai/models；用户端选模与新会话绑定
- 禁用模型后会话只读（5009）；chat 按会话 modelCode 调 DashScope
- 前端 AiModels 页、助手模型选择器与 localStorage
- 单测、AiModelManagementApiIT、Playwright E2E；e2e Profile 关闭注解限流
- 技术实施文档与验收报告；移除过期冲突分析文档

Co-authored-by: Cursor <cursoragent@cursor.com>

jog-frontend/src/router/index.js

@@ -103,6 +103,12 @@ const routes = [
         component: () => import('@/views/admin/Categories.vue'),
         meta: { title: '分类管理', requiresAuth: true, requiresAdmin: true },
       },
+      {
+        path: 'ai-models',
+        name: 'AdminAiModels',
+        component: () => import('@/views/admin/AiModels.vue'),
+        meta: { title: 'AI 模型', requiresAuth: true, requiresAdmin: true },
+      },
     ],
   },
 ]