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>

app/sitemap.ts

@@ -0,0 +1,32 @@
+import type { MetadataRoute } from 'next';
+import { getConfigOrNull } from '@/lib/config';
+import { buildSiteShape } from '@/lib/siteShape';
+import { publicPaths } from '@/lib/publicPages';
+import { absoluteUrl } from '@/lib/siteUrl';
+
+/**
+ * sitemap.xml (#472).
+ *
+ * What goes in is decided by `publicPaths()`, the same function the feed uses,
+ * because a sitemap lists exactly what access control otherwise hides and a
+ * second implementation of that judgement would eventually disagree with the
+ * first.
+ */
+export const dynamic = 'force-dynamic';
+
+export default async function sitemap(): Promise<MetadataRoute.Sitemap> {
+  const config = getConfigOrNull();
+
+  // A sitemap needs absolute URLs and this route has no request context to
+  // derive a host from. Without a configured site URL there is nothing valid
+  // to emit, and an empty sitemap is better than a wrong one.
+  if (!config?.siteUrl) return [];
+
+  const shape = await buildSiteShape().catch(() => null);
+  if (!shape) return [];
+
+  return publicPaths(shape).flatMap((path) => {
+    const url = absoluteUrl(config.siteUrl, path);
+    return url ? [{ url, changeFrequency: 'weekly' as const }] : [];
+  });
+}