feat(photos): full EXIF metadata extraction, backfill and info panel

- backend: switch EXIF parser to dsoprea/go-exif/v3 (all recognised tags, numeric normalization); store in photos.exif jsonb (migration 000003); add storage.Get and cmd/backfill-exif to backfill existing photos from S3 originals
- frontend: info panel renders all EXIF attributes with RU labels, enum translation and units (1/N, f/N, mm, EV); service tags hidden
- viewer: remove make-cover action (cover managed from panel only), icon-only download
- openspec: sync lightroom-workspace-ui artifacts (EXIF, cover-from-panel) and add plan for configurable info attributes/labels stored in user profile

frontend/src/routes/(app)/albums/[id]/photos/[photoId]/+page.svelte

@@ -4,7 +4,6 @@
 	import { api } from '$lib/api';
 	import Viewer from '$lib/components/Viewer.svelte';
 	import ConfirmDialog from '$lib/components/ConfirmDialog.svelte';
-	import { albums } from '$lib/stores/albums.svelte';
 	import { auth } from '$lib/stores/auth.svelte';
 	import type { Album, Photo } from '$lib/types';
 
@@ -15,7 +14,6 @@
 	let role = $state('');
 	let loading = $state(true);
 	let error = $state('');
-	let saved = $state(false);
 	let pendingDelete = $state<Photo | null>(null);
 	let deleting = $state(false);
 
@@ -51,17 +49,6 @@
 		if (p) goto(`/albums/${albumId}/photos/${p.id}`, { replaceState: true, noScroll: true });
 	}
 
-	async function makeCover(photo: Photo) {
-		if (!canEdit) return;
-		try {
-			await albums.setCover(albumId, photo.id);
-			saved = true;
-			setTimeout(() => (saved = false), 2000);
-		} catch (e) {
-			error = (e as Error).message;
-		}
-	}
-
 	async function removePhoto(photo: Photo) {
 		pendingDelete = photo;
 	}
@@ -104,18 +91,13 @@
 	</div>
 {:else}
 	<div class="flex h-full flex-col">
-		{#if saved}
-			<p class="bg-success/10 text-success px-3 py-1 text-center text-xs">Обложка обновлена</p>
-		{/if}
 		<div class="min-h-0 flex-1">
 			<Viewer
 				{photos}
 				{index}
-				{canEdit}
 				{canDelete}
 				onClose={close}
 				onIndexChange={change}
-				onMakeCover={makeCover}
 				onDelete={removePhoto}
 			/>
 		</div>