Jellyfin MPV Shim

Changes: - Fix mpv_ext_no_ovr and OSC interaction (#499) - Fix intro skip and custom seek bindings (#491) - Fix python 3.14 compat issues on macOS (#487) - Fix transcode termination failure (#492, #481) - Prevent crash when opening menu during stream load (#493) - Fix mpv_ext_no_ovr and OSC interaction (#499) - Fix intro skip and custom seek bindings (#491) - Make Pillow dependency optional (#494) - Fix system tray icon to use X11 (#506) - Fix H.265 transcode preference not being used in some cases (#531) - Fix capability reporting, state sync, and websocket reconnect (#515) - Fix application menu handling (#528) - Fix installer not able to close application (#529) - Add CLI flags to configure/update/delete account (#519) - Use Jellyfin logo as window icon and idle background (#513) - Add path substitutions feature (#511) - Make external mpv process start retries and retry delay configurable in settings (#504) - Implement local-network priority for Jellyfin server connections (#502) - Added new language_config feature, allows mpv-style alang/slang config, conditional preferences, and more - Fix issue where volume 0% is reported as 100% (#497) - Add --help, --debug, --gui, and --no-gui options (#477) - Make connection retry and health check more robust. - Fix issue where ipv6 connections always register as remote. (#482) - Fix issue where OSC menu didn't have background, affecting usability. - Upgrade mpv version. - Replace webview-based display mirror with tkinter-based one. About Windows Downloads: - If your CPU is older than roughly 2013 or you get a 0xc0000142 error you need to use the LEGACY64 build. - You do not need administrator rights to install the software. - You can avoid warnings on files by unblocking the file in the properties dialog. - You can manually build a release using these instructions.