fix: add /tag/ to hasPageMetadata check in layout (#606)

The layout was rendering default OG tags even for tag pages because
/tag/ wasn't in the hasPageMetadata list, causing crawlers to use
the first (default) tags instead of the page-specific ones.

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

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

authored by zzstoatzz.io Claude Opus 4.5 and committed by GitHub aa17bcab f0632f49

Changed files
+1
frontend
src
+1
frontend/src/routes/+layout.svelte
··· 29 29 $page.url.pathname === '/' || // homepage 30 30 $page.url.pathname.startsWith('/track/') || // track detail 31 31 $page.url.pathname.startsWith('/playlist/') || // playlist detail 32 + $page.url.pathname.startsWith('/tag/') || // tag detail 32 33 $page.url.pathname === '/liked' || // liked tracks 33 34 $page.url.pathname.match(/^\/u\/[^/]+$/) || // artist detail 34 35 $page.url.pathname.match(/^\/u\/[^/]+\/album\/[^/]+/) // album detail