Two Plex-port fixes (both in the Plex play/data path):
1. Progressive streaming — play starts in ~1s instead of ~10s. play_plex_audible
no longer downloads the whole file before play_data; it resolves only the
part URL (new additive qbz_plex::plex_resolve_part_url, no body GET) and feeds
it into the player's streaming source (play_streaming_dynamic) via a shared
feeder module (remote_stream.rs, extracted from the QConnect renderer's HTTP
feeder — both now share it). Bit-perfect preserved: the original /file bytes
are streamed (no transcode), device init derives from the decoded stream; the
protected audio backend is untouched. Cast/DLNA keep the whole-file path.
Falls back to whole-file play_data on a non-direct part / streaming-setup error.
2. Re-sync no longer wipes hydrated quality — the sync did plex_cache_clear()
(full wipe) BEFORE the per-section save_tracks, defeating save_tracks' COALESCE
hydration carry-over, so already-hydrated albums reverted to a bare FLAC badge
on every settings-open / background-refresh / section-toggle. Replaced the full
wipe with a new additive plex_cache_prune_sections(keep) that removes only the
DE-selected sections, keeping the selected sections (and their hydration);
save_tracks then re-applies its per-section carry-over.
cc
vicrodh
b37c29af14