spa-routes

SPA roots-vs-features split for LobeHub — thin route segments under `src/routes/` delegate to domain components under `src/features/`. Use when editing `src/routes/` segments, `src/spa/router/desktopRouter.config.tsx` or `desktopRouter.config.desktop.tsx` (MUST update both together — `desktopRouter.sync.test.tsx` enforces this), `mobileRouter.config.tsx`, `popupRouter.config.tsx`, or moving UI/logic between `routes/` and `features/`. Triggers on `desktopRouter.config`, `mobileRouter.config`, `popupRouter.config`, `src/routes/**`, `src/features/**`, 'add a route', 'new page', 'route segment', '路由'.