refactor(stage9): 后端业务域目录形状统一

- 每个域现在都是 src/server/routes/<domain>/ 目录：
  vehicles/routes.ts（原 routes/vehicles.ts）、vehicle-heatmap/{routes,model}.ts、
  hydrogen-heatmap/{routes,model}.ts、ele/routes.ts、feedback/routes.ts。
- 命名约定：index.ts 是聚合器（挂子路由），routes.ts 是叶子路由。mileage/energy/
  scheduling 保持 index.ts 聚合，其余统一为 routes.ts。
- 纯移动与改名，未改动任何 SQL、参数顺序、路由挂载前缀或处理器逻辑。
  import 改写由一次性 codemod 完成；vehicles/repository.test.ts 读取的源码路径同步更新。
- docs/ARCHITECTURE.md 补充"后端业务域形状"表，并如实标注 ele / feedback 尚未拆出
  repository（这两个域缺 SQL 指纹测试，建议先补测试再拆）。

lint / test(139) / build 全绿，可达性 0 未引用文件。

src/server/app.ts

@@ -4,14 +4,14 @@ import { readOnlyMiddleware } from './middleware/read-only.js';
 import { cors } from 'hono/cors';
 import authRouter from './auth/login.js';
 import { authMiddleware } from './middleware/auth.js';
-import eleRouter from './routes/ele/index.js';
+import eleRouter from './routes/ele/routes.js';
 import energyRouter from './routes/energy/index.js';
-import feedbackRouter from './routes/feedback/index.js';
-import hydrogenHeatmapRouter from './routes/hydrogen-heatmap.js';
+import feedbackRouter from './routes/feedback/routes.js';
+import hydrogenHeatmapRouter from './routes/hydrogen-heatmap/routes.js';
 import mileageRouter from './routes/mileage/index.js';
 import schedulingRouter from './routes/scheduling/index.js';
-import vehicleHeatmapRouter from './routes/vehicle-heatmap.js';
-import vehiclesRouter from './routes/vehicles.js';
+import vehicleHeatmapRouter from './routes/vehicle-heatmap/routes.js';
+import vehiclesRouter from './routes/vehicles/routes.js';
 
 /**
  * 创建 HTTP 应用，但不监听端口、不访问数据库，也不启动后台任务。