feat(web): sidebar root folder + folder counts, drill-in colors/tags/ratings, click semantics rework

Sidebar
- New `/` root-folder entry at the top of the Folders group. Active
  when the timeline is scoped to root; the photo grid post-filters to
  `Path === ''` because PhotoPrism's `path:` operator can't express an
  exact-root match. Collapsible chevron, persisted to its own
  localStorage key, and a kebab carrying just "New subfolder".
- Per-folder count badges. `/api/v1/photos?q=path:X&count=1000` per
  folder in parallel via `listFolderCounts`; root count derived from
  `config.count.all − Σ subfolder counts`.
- Folder tree starts at depth=1 under the root so nested rows indent
  visually relative to `/`.
- Footer matches the Toolbar / action-bar h-9 height.

Timeline interaction
- Single click on a tile selects only that tile (clears others); the
  preview now lives on dblclick. Modifier clicks still go through
  `gridKeyNav`'s document handler (shift = range, cmd/ctrl = toggle).
- `x` (archive) now actually archives — PhotoPrism's photo PUT
  silently drops the Archived field, so we route through
  /batch/photos/{archive,restore} the same way the BulkActionBar
  already did. Mirror for `u`.
- Preview close restores the timeline focus + scrolls the last-shown
  photo into view via `forcedExpand`+`scrollTileIntoView` so it
  actually mounts (selection ring would otherwise stay invisible when
  the user navigated far in preview).
- `applyFolderScope` only narrows the timeline to root when the active
  view is a folder view (no heap / search / non-default section), so
  label clicks / heap views / favorites no longer drop subfolder
  photos.

Action bar
- Inline `h-9` row at the bottom of the main column (not `fixed`),
  matching the Toolbar's visual language. Right sidebar stays full
  height — the bar only spans the timeline width.
- Approve action wired for the review pile.

Colors / Tags / Ratings drill-ins
- New shared `PhotoGrid` component owning tile rendering, selection
  styling, single-click-selects + dblclick-previews, and `setOrder`
  for arrow-key nav.
- Each route's drill-in `<main>` carries `use:gridKeyNav` and a
  trailing `<BulkActionBar />` so shift/cmd/ctrl click, arrow keys,
  and the keyboard shortcuts work the same as the timeline.
- Tags switches from `goto('/?q=label:…')` to an in-place drill-in
  with a back button, mirroring `/colors`'s flow.
- Category cards + drill-in photo cards honour the global
  `view.thumbnailSize` (XS–XL) so the timeline's size selector now
  reaches into all four grids.

Settings
- General-settings dialog merges Appearance into UI and switches free
  text inputs to selects for the PhotoPrism theme / language / start
  page / map style (the value-from-server prepends if it's outside
  the curated list so we never silently rewrite a custom value). Time
  zone uses `<datalist>` with `Intl.supportedValuesOf('timeZone')`.

Sidecar
- Heap convert runs reindex synchronously per source path so the
  client's invalidate-and-refetch sees the moved files.

Inbox
- New /inbox route stub for the upcoming import workflow.

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

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

@@ -60,6 +60,11 @@
 		 *  `filters.folderPath` matches (the sidebar nav case); the picker
 		 *  passes its own selection so the dialog has independent state. */
 		selectedPath?: string | null;
+		/** Optional per-path photo count. When provided, each row renders a
+		 *  compact badge with the count — matching the heaps section's
+		 *  "{n} photos" affordance. Undefined keeps the badge off entirely
+		 *  (the picker dialog doesn't need it). */
+		counts?: Record<string, number>;
 	}
 	let {
 		nodes,
@@ -69,7 +74,8 @@
 		onDelete,
 		onCreateChild,
 		readonly = false,
-		selectedPath
+		selectedPath,
+		counts
 	}: Props = $props();
 
 	// Auto-expanded folders, persisted to localStorage so the tree state
@@ -114,7 +120,7 @@
 				with the px-2 of Views/Heaps rows; +12px per nested level.
 			-->
 			<div
-				class="group flex h-[24px] items-center rounded text-[12px] leading-tight hover:bg-accent"
+				class="group flex h-[24px] items-center rounded pr-2 text-[12px] leading-tight hover:bg-accent"
 				class:bg-primary={active}
 				class:text-primary-foreground={active}
 				class:hover:bg-primary={active}
@@ -137,7 +143,7 @@
 					<span class="inline-block h-[18px] w-4" aria-hidden="true"></span>
 				{/if}
 				<button
-					class="flex flex-1 items-center truncate text-left"
+					class="flex min-w-0 flex-1 items-center truncate text-left"
 					class:px-1={hasChildren || depth > 0}
 					onclick={() => onPick(node.path)}
 					ondblclick={readonly ? undefined : () => onRename?.(node.path)}
@@ -145,11 +151,23 @@
 				>
 					<span class="truncate">{node.name}</span>
 				</button>
+				{#if counts && counts[node.path] !== undefined}
+					{@const n = counts[node.path]}
+					<span
+						class="ml-auto shrink-0 rounded px-1 text-[10px] tabular-nums {active
+							? 'bg-primary-foreground/15 text-primary-foreground'
+							: 'bg-secondary text-muted-foreground'}"
+					>
+						{n >= 1000 ? '1000+' : n}
+					</span>
+				{/if}
 				{#if !readonly}
-					<!-- Hover-revealed kebab. Reserves zero width when idle so the
-					     row stays compact; expands on hover and stays visible while
-					     the menu is open. Suppressed in readonly mode (picker). -->
-					<div class="mr-1">
+					<!-- Hover-revealed kebab. `display: none` until row hover
+					     (or while the menu is open via has-[[data-state=open]])
+					     so the count holds the row's right edge by default
+					     and the kebab pushes it left when it appears.
+					     Suppressed in readonly mode (picker). -->
+					<div class="ml-1 hidden group-hover:block has-[[data-state=open]]:block">
 						<KebabMenu label="Folder actions">
 							<Item
 								class="flex cursor-pointer items-center gap-2 rounded px-2 py-1.5 text-[12px] outline-none hover:bg-accent focus:bg-accent"
@@ -187,6 +205,7 @@
 					{onCreateChild}
 					{readonly}
 					{selectedPath}
+					{counts}
 				/>
 			{/if}
 		</li>