feat(web): /tags tabs + keyword surfacing + dup tab restyle

- /tags hosts four tabs (Labels (auto) / Keywords / Ratings / Colors),
  URL-driven with pagination on the label + keyword grids; ratings and
  colors stay as fixed buckets.
- /duplicates tabs (Stacks / Cross-folder) restyled to pill row in the
  Toolbar to match /tags; tab state moved into the route and bound to
  ?tab=...
- New aggregateKeywords() service fans out per-photo getPhoto calls so
  user-typed Details.Keywords surface on /tags (PhotoPrism's /labels
  only returns classifier output).
- RightSidebar renders photo.Labels[] as dashed-border chips after the
  Keywords section, each linking to /?q=label:slug.
- /colors and /ratings routes redirect to /tags?tab=colors|ratings so
  old bookmarks still land somewhere useful; LeftSidebar drops their
  entries and the Tags badge now sums labels + ratings + colors.
- listFolderCounts dedupes by UID (merged=false returns one row per
  FILE, so HEIC+JPG / Live Photo / RAW+JPG pairs were inflating folder
  counts ~2x).

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

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

@@ -352,9 +352,19 @@
 		{ kind: 'route', href: '/inbox', label: 'Inbox', getCount: () => importQuery.data?.files },
 		{ kind: 'section', id: 'favorites', label: 'Favorites', getCount: () => configQuery.data?.count?.favorites },
 		{ kind: 'route', href: '/map', label: 'Map', getCount: () => configQuery.data?.count?.places },
-		{ kind: 'route', href: '/ratings', label: 'Ratings', getCount: () => ratingsCount },
-		{ kind: 'route', href: '/colors', label: 'Colors', getCount: () => colorsCount },
-		{ kind: 'route', href: '/tags', label: 'Tags', getCount: () => configQuery.data?.count?.labels }
+		// Tags hosts four tabs (Labels (auto) / Keywords / Ratings / Colors);
+		// the badge shows total labels + keywords + ratings + colors so the
+		// number reflects the combined "things you can filter by" surface.
+		{
+			kind: 'route',
+			href: '/tags',
+			label: 'Tags',
+			getCount: () => {
+				const labels = configQuery.data?.count?.labels;
+				if (labels === undefined) return undefined;
+				return labels + ratingsCount + colorsCount;
+			}
+		}
 	];
 
 	const manageViews: ViewItem[] = [