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

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Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

lib/albumNav.ts

@@ -0,0 +1,65 @@
+/**
+ * Sequential album navigation — the "previous / next album" pair at the foot of
+ * an album detail page, so a visitor drifting through the portfolio is not
+ * dropped at a dead end (#483).
+ *
+ * The order deliberately comes from whatever list the visitor just came
+ * through — the surrounding subpage, or the standalone album list — rather than
+ * from a separate ordering of its own. A "next" that disagreed with the grid
+ * the visitor was looking at a moment ago would be worse than no control.
+ *
+ * Neighbours are not wrapped around: the first album has no previous and the
+ * last has no next. Wrapping would guarantee a link in every position, but it
+ * also sends someone who reaches the end of a sequence back to its start with
+ * no sign that they have been round.
+ */
+
+/** The fields of an album this module needs. Structural, so `ImmichAlbum` fits. */
+export interface AlbumNavCandidate {
+  id: string;
+  slug: string;
+  albumName: string;
+}
+
+export interface AlbumNavLink {
+  href: string;
+  name: string;
+}
+
+export interface AlbumNavPair {
+  prev?: AlbumNavLink;
+  next?: AlbumNavLink;
+}
+
+/**
+ * The neighbours of `currentId` within `siblings`, in that list's own order.
+ *
+ * `basePath` is the prefix the album slugs hang off: `''` for standalone albums
+ * (`/album-slug`) or `/subpage-slug` for albums inside a subpage.
+ *
+ * Returns an empty pair when the album is not in the list, or when it is the
+ * only one — both cases mean there is nothing to offer, and the caller renders
+ * nothing.
+ */
+export function albumNeighbours(
+  siblings: readonly AlbumNavCandidate[],
+  currentId: string,
+  basePath = '',
+): AlbumNavPair {
+  const index = siblings.findIndex((a) => a.id === currentId);
+  if (index === -1 || siblings.length < 2) return {};
+
+  const href = (album: AlbumNavCandidate) => `${basePath}/${album.slug}`;
+  const link = (album: AlbumNavCandidate): AlbumNavLink => ({
+    href: href(album),
+    name: album.albumName,
+  });
+
+  const previous = index > 0 ? siblings[index - 1] : undefined;
+  const following = index < siblings.length - 1 ? siblings[index + 1] : undefined;
+
+  return {
+    ...(previous ? { prev: link(previous) } : {}),
+    ...(following ? { next: link(following) } : {}),
+  };
+}