Navidrome fix:
- createPlaylist and other write operations now use POST instead of
GET. Large playlists (161+ tracks) exceeded URL length limits when
all songId params were in the query string, causing silent truncation
(e.g., only 6 of 161 tracks added). POST sends params as form body
with no size limit.
- Write operation timeout bumped to 30s (was 10s)
- _WRITE_ENDPOINTS set defines which Subsonic endpoints use POST
UX fix:
- Mirrored playlist cards now show "161/161 discovered on Spotify"
instead of just "161/161 discovered" — clarifies that discovery
means metadata matching, not library ownership
8e41feaade
