fix(sidebar): paginate folder counts; drop bogus all:true from labels query

Two distinct bugs were causing left-sidebar badges to under-report:

1. sidecar/folders/counts hard-capped each PP /photos call at count=1000
   and deduped UIDs from that single page. Any folder with >1000 file
   rows under it (typical for a multi-year root scan with HEIC sidecars)
   silently lost everything past row 1000. On this library the root
   badge reported 912 while the year subfolders summed to 1175. Loop
   offsets instead, breaking when PP returns a short page.

2. The Labels-badge query passed all:true label:* to PP, which 400s with
   "Unable to do that" - none of the other bucket queries prefix
   all:true. Drop it; the scoped() helper already injects the user's
   path clause when applicable.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web/src/lib/components/layout/LeftSidebar.svelte

@@ -143,7 +143,7 @@
 	// BasePath shape and never fall back to the category-count.
 	const labelsCountQuery = createQuery<number>(() => ({
 		queryKey: ['photos', 'scoped-count', 'labels', userBasePath(), isAdminUser],
-		queryFn: () => countPhotos(scoped('all:true label:*')),
+		queryFn: () => countPhotos(scoped('label:*')),
 		enabled: isAuthenticated(),
 		staleTime: 60_000
 	}));