web(sidebar): nest Hidden under Review submenu

Hidden is the resting place for photos dismissed during review, so it
groups naturally with the Review subitems. Stays a section-nav button
(keeping its scoped count badge); only Archive remains as a flat Manage
entry.

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

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

@@ -542,10 +542,10 @@
 
 	// Review is rendered separately below as a pure expandable toggle
 	// (mirroring Tags — no /review landing entry from the sidebar,
-	// navigation only via subitems). This list carries the flat Manage
-	// entries that follow it.
+	// navigation only via subitems, with Hidden tucked in alongside the
+	// tab subitems). This list carries the flat Manage entries that
+	// follow it.
 	const manageViews: ViewItem[] = [
-		{ kind: 'section', id: 'hidden', label: 'Hidden', getCount: () => hiddenBadge },
 		{ kind: 'section', id: 'archive', label: 'Archive', getCount: () => archivedBadge }
 	];
 
@@ -926,6 +926,33 @@
 					<span class="truncate">{t.label}</span>
 				</a>
 			{/each}
+			<!--
+				Hidden lives under Review since it's the resting place for
+				photos dismissed during review. Section-nav (not a ?tab=),
+				so it's a button that flips filters.section like the flat
+				Manage entries — just with the subitem indent.
+			-->
+			{@const hiddenActive = isActive('hidden')}
+			<button
+				type="button"
+				class="flex h-[22px] w-full items-center rounded pr-2 text-left text-[12px] leading-tight hover:bg-accent"
+				class:bg-primary={hiddenActive}
+				class:text-primary-foreground={hiddenActive}
+				class:hover:bg-primary={hiddenActive}
+				style="padding-left: 36px;"
+				onclick={() => navigateTo('hidden')}
+			>
+				<span class="truncate">Hidden</span>
+				{#if hiddenBadge !== undefined}
+					<span
+						class="ml-auto flex h-4 min-w-[24px] flex-shrink-0 items-center justify-center rounded px-1 text-[10px] tabular-nums {hiddenActive
+							? 'bg-primary-foreground/15 text-primary-foreground'
+							: 'bg-secondary text-muted-foreground'}"
+					>
+						{hiddenBadge}
+					</span>
+				{/if}
+			</button>
 		{/if}
 		{#each manageViews as v (v.kind === 'section' ? `s:${v.id}` : `r:${v.href}`)}
 			{@render viewRow(v)}