Sort playlist using announced track name

[paulpv]

Summary

Update playlist ordering so it sorts by the same normalized name we use for announcements (the short/friendly title), rather than the raw filename.

Proposed work

• Reuse the announce-name helper when building the sortable key for each track.
• Ensure the sort happens after we apply announce rules or metadata overrides so consistent names are used across the app.
• Provide a way to toggle between the new announced-name sort and the existing filename order if needed (could be a settings switch).
• Confirm the sorted order persists between sessions and handles newly added folders gracefully.
• Update manual testing guidance in README.md for verifying sort order with mixed naming conventions.