Reworked video downloads and livestream resolution for improved reliability across Windows, Linux and macOS.

• MCCinema now downloads the correct native yt-dlp binary for the server's operating system and architecture.
• MCCinema now uses an existing Deno or Node.js installation when available, or downloads its own private Deno runtime.
• Downloaded tools are checksum-verified and health-checked before use.
• Tool updates are performed safely, retaining the last working version if an update fails.
• Added configurable stable/nightly yt-dlp channels and automatic update intervals.
• MCCinema now attempts to use the ffmpeg executable bundled with JavaCV, falling back to a system installation when necessary.
• Downloads and livestream playback now continue automatically after first-time media setup completes.
• Added /mcc media for viewing yt-dlp, JavaScript runtime and cookie status.
• Added /mcc media retry for repairing or updating the managed media tools.
• Improved user-facing error messages for offline streams, rate limits, unsupported URLs, authentication failures and broken tool installations.

Improved YouTube cookie handling.

• Cookies are now optional and public media is always attempted without them first.
• Cookies are only used after YouTube reports that authentication is required.
• youtube_cookies.txt is validated as a Netscape-format cookie file before use.
• Invalid, expired and symbolic-link cookie files are rejected with clearer diagnostics.
• Cookie changes are detected without requiring a plugin reload.

Improved livestream playback.

• Removed the dependency on Python-based yt-dlp launchers.
• Required HTTP headers from yt-dlp are now passed to the livestream connection.
• Expired or stalled livestream URLs are automatically resolved again.
• Added reconnect handling and reduced repeated stall messages in the server log.
• The currently playing video is only replaced after the new livestream connection has loaded successfully.

Added interactive zooming and positioning for local videos.

• Use /mcc crop <screen> while a local video is playing.
• Use the mouse wheel to zoom and W/A/S/D to position the image.
• Hold sneak for more precise adjustments and press F to reset the preview.
• Use /mcc crop save, /mcc crop reset or /mcc crop cancel to finish editing.
• Crop settings are persisted separately for each video and reused during future playback.

Improved audio extraction and conversion.

• Audio is now extracted and encoded using the FFmpeg libraries bundled with JavaCV.
• Added parallel audio chunk encoding and detailed conversion progress.
• Improved mono/stereo downmixing and Vorbis chunk padding.
• Incomplete or outdated audio caches are detected and rebuilt automatically.

Improved screen and map cleanup.

• Newly created screen item frames and map items are tagged with persistent screen and tile information.
• /mcc delete now removes the screen's item frames and map items automatically.
• Legacy screens are also detected using their placement and map IDs.

Added the mccinema.crop and mccinema.media permissions.