feat(preview): inline split-pane preview + sidebar metadata pass

Replace the fullscreen PreviewOverlay with an inline top pane above
each grid surface. SplitGrid + InlinePreview render the focused
photo/video inside the host page; a resizableVertical action drives
the divider and the height persists via the view store. Applied to
the timeline, /tags drill-in, /review cause tabs, /photo/[uid], and
/map. selection.focused is now the single source of truth for both
the inline pane and the right sidebar — preview.svelte store and
PreviewOverlay are removed.

Sidebar: drop the thumb; lead with icon-led filename and folder
rows that match the date/place rhythm. Move dims+size to the top
(below date) and camera/lens/exposure into the collapsible File
section. Read-only spans share the input padding so the text column
aligns across rows. Folder row sits between date and dims+size.

VideoPlayer: stop forcing width/height: 100% so videos honour their
intrinsic aspect ratio inside the pane. Key the player on file hash
in InlinePreview so navigating between videos remounts the element
and autoplay fires again.

Sidebar (LeftSidebar): switch the labels badge to a dedicated
countPhotos('label:*') query so it reports photos with a label
rather than PhotoPrism's category roll-up.

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

web/src/lib/components/timeline/PhotoGrid.svelte

@@ -21,7 +21,6 @@
 		setFocused,
 		setOrder
 	} from '$lib/stores/selection.svelte';
-	import { openPreview } from '$lib/stores/preview.svelte';
 	import { view } from '$lib/stores/view.svelte';
 	import { type PpPhoto } from '$lib/types/photoprism';
 	import PhotoTile from './PhotoTile.svelte';
@@ -77,11 +76,17 @@
 	function onDblclick(e: MouseEvent, uid: string) {
 		if (e.shiftKey || e.metaKey || e.ctrlKey) return;
 		e.preventDefault();
-		openPreview(uid, order);
+		selection.ids.clear();
+		selection.ids.add(uid);
+		setFocused(uid);
+		setAnchor(uid);
 	}
 
 	function onOpenPreview(uid: string) {
-		openPreview(uid, order);
+		selection.ids.clear();
+		selection.ids.add(uid);
+		setFocused(uid);
+		setAnchor(uid);
 	}
 </script>