fix: reuse Elementum packs for PlayNext

[Therand90]

Summary

• preserve and classify Elementum pack metadata during source resolution
• reuse the same Elementum torrent URI for the next episode when the selected source is a compatible season or multi-season pack
• keep global autoplay disabled: no new torrent is selected automatically
• fall back to Jacktook's normal processed source list when the selected source cannot be safely reused
• scope PlayNext actions to one playback session so stale player instances cannot enqueue or scrobble multiple episodes
• use Player.play() for the internal PlayNext handoff after the original plugin resolution has completed

Pack handling

The implementation distinguishes:

• single episode releases such as S05E03 or 5x03
• season packs such as S05
• explicit multi-season packs such as S01-S06
• generic complete-series packs, handled conservatively when their included seasons are not explicit

A season boundary is crossed only when the selected pack explicitly includes the target season. Otherwise Jacktook falls back to the regular source selector.

Behavior

For a compatible Elementum pack, Jacktook keeps the existing uri and updates the TV playback metadata (show, season, and episode).

This reuses the torrent the user already selected. It does not enable global autoplay and does not select a different torrent automatically.

For non-pack or incompatible sources, Jacktook uses the normal processed search results and displays the manual source selector.

Testing

• 100 focused unit tests passed
• manually validated on LibreELEC/Kodi with Elementum and a Prowlarr season pack
• pressing Next on S05E03 starts S05E04 from the same torrent
• allowing the PlayNext timer to expire also starts S05E04
• confirmed that only one playback session queues, launches, and scrobbles the next episode

Kodi may briefly restore the episode list between the two playback sessions before the next video opens.