perf(base): batch page-cell resolution via microtask loader

Per-cell useResolvedPages([id]) calls each mounted with a unique
React Query key, so a grid with 20 page-typed cells fired 20 requests on
first paint. A shared loader now accumulates incoming ids within a
microtask, fires a single POST for the union, and fans the subset each
caller asked for back to them. Cells keep their own cache entry + null
handling; they just share the underlying network call.

Also renames /bases/pages/resolve → /bases/pages/expand — the old name
collided with other "resolve" semantics in the codebase.

apps/server/src/core/base/controllers/base.controller.ts

@@ -143,7 +143,7 @@ export class BaseController {
   }
 
   @HttpCode(HttpStatus.OK)
-  @Post('pages/resolve')
+  @Post('pages/expand')
   async resolvePages(
     @Body() dto: ResolvePagesDto,
     @AuthUser() user: User,