release: v0.13.0 (#535)

Twenty-nine commits since v0.12.0. See CHANGELOG.md for the full list
and the upgrade notes.

Ten additions — the SEO package (site URL, robots.txt, sitemap.xml,
JSON-LD), slideshow mode, opt-in original downloads, copy-link,
previous/next album navigation, alt text from the Immich description,
per-album location precision, the update notice, a Help tab, and a
subpage cover grid separate from its photo grid. Two fixes: CJK album
slugs, and the lightbox control bar.

Photo of the Day (#476) was built on `dev` and reverted as not planned;
it never appears in a release.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

https://claude.ai/code/session_01DmsHVRL9yQvckUB1ZpVWre

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: ralksta <ralksta@users.noreply.github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

lib/structuredData.ts

@@ -0,0 +1,60 @@
+/**
+ * The JSON-LD payload for an album page (#472).
+ *
+ * `ImageGallery` with an `ImageObject` for the cover is the annotation that
+ * pays off for a photography portfolio: it is what a search result can show,
+ * and it is where `creator` and `license` belong.
+ *
+ * Built as a pure function so the shape can be asserted without rendering, and
+ * so the "no site URL, no structured data" rule is stated once.
+ */
+
+export interface AlbumStructuredDataInput {
+  siteUrl: string | null;
+  /** Absolute URL of the album page. */
+  pageUrl: string | null;
+  albumName: string;
+  description?: string;
+  /** Absolute URL of the cover image, if there is one. */
+  coverUrl?: string | null;
+  /** The photographer, for `creator`. */
+  creator?: string;
+  /** A licence URL or short identifier, e.g. a Creative Commons link. */
+  license?: string;
+  photoCount?: number;
+}
+
+export function albumStructuredData(
+  input: AlbumStructuredDataInput,
+): Record<string, unknown> | null {
+  // Structured data is a set of claims about URLs. Without an absolute site URL
+  // there is nothing truthful to claim, so nothing is emitted.
+  if (!input.siteUrl || !input.pageUrl) return null;
+  if (!input.albumName.trim()) return null;
+
+  const creator = input.creator?.trim()
+    ? { '@type': 'Person', name: input.creator.trim() }
+    : undefined;
+  const license = input.license?.trim() || undefined;
+
+  return {
+    '@context': 'https://schema.org',
+    '@type': 'ImageGallery',
+    name: input.albumName.trim(),
+    url: input.pageUrl,
+    ...(input.description?.trim() ? { description: input.description.trim() } : {}),
+    ...(typeof input.photoCount === 'number' ? { numberOfItems: input.photoCount } : {}),
+    ...(creator ? { creator } : {}),
+    ...(license ? { license } : {}),
+    ...(input.coverUrl
+      ? {
+          image: {
+            '@type': 'ImageObject',
+            contentUrl: input.coverUrl,
+            ...(creator ? { creator } : {}),
+            ...(license ? { license } : {}),
+          },
+        }
+      : {}),
+  };
+}