fix(mac): apply rotation metadata and reach 100% on progress bar

[kdroidFilter]

Summary

• Portrait videos no longer render sideways on JVM/macOS (Portrait videos render rotated incorrectly on desktop (rotation metadata not applied) #202). Set an AVVideoComposition (built from the asset's preferred transform) on the AVPlayerItem so AVPlayerItemVideoOutput delivers pixel buffers already rotated to display orientation. Skipped for HLS streams whose tracks aren't synchronously available.
• Progress bar now reaches the end of the video. The checkLoopingAsync had a 0.5 s position-based fallback that triggered pauseInBackground() half a second before the real end, freezing sliderPos at (duration - 0.5) / duration — visibly short for short videos. Removed the fallback; we now trust AVPlayerItemDidPlayToEndTime, which fires reliably on macOS for both file and HLS playback.
• gitignore the prebuilt darwin-aarch64/ and darwin-x86-64/ dylib resource directories so they don't accidentally get committed.

Test plan

• Open a portrait video recorded on a phone (e.g. the sample from Portrait videos render rotated incorrectly on desktop (rotation metadata not applied) #202) — it should render upright instead of sideways.
• Verify aspect ratio remains correct for landscape videos.
• Play a short video to completion — the progress slider should visibly reach 100% before pausing.
• Loop mode: enable loop on a short video and confirm seamless restart.
• HLS playback still works (no composition is applied; behavior unchanged).
• Rebuild dylibs via mediaplayer/src/jvmMain/native/macos/build.sh for both arm64 and x86_64 and confirm clean compilation.