perf: optimize routing, media, and SEO

[AlejandroAkbal]

Summary

• flatten posts filter queries and remove qs from the router path
• defer toast/runtime clients, sidebar/search UI, home history, and post media controls
• add tag landing pages, richer breadcrumbs/schema, consistent favicon URLs, and llms.txt

Testing

• npm test
• npm run build

Notes

• Split into conventional commits by feature area for easier review.

Summary by CodeRabbit

• New Features

  • Tag landing pages and localized canonical URLs; new client toaster and lazy toast composable; several non-interactive post-action fallbacks; Portuguese, German, and French locales.

• Improvements

  • Widespread Schema.org breadcrumbs; smarter LCP-aware media loading and deferred video/player init; unified favicon helper; more robust flat filter/query handling and scroll/top detection.

• Changes

  • Tooling/docs switched to pnpm; build/runtime tweaks for source-map/sentry gating.

• Tests

  • Expanded E2E and unit tests for routing, images, and canonical behavior.