Add JKVideo - Bilibili-like React Native client

[tiajinsha]

Description

Adding JKVideo to the Open Source Apps section.

JKVideo is a feature-rich open-source Bilibili-like client demonstrating several advanced React Native techniques:

• DASH playback: Converts Bilibili DASH stream to local MPD via buildDashMpdUri() for native ExoPlayer decoding (1080P+ / 4K HDR)
• Real-time danmaku: XML timeline sync + 5-lane floating overlay; live danmaku via WebSocket with captain badge & gift counting
• WBI request signing: Pure TypeScript MD5, no external crypto deps, 12h nav cache
• Inline video feed: BigVideoCard with auto-play (muted), gesture seek, progress/buffer bar
• Global mini player: Persistent bottom float player across navigation via Zustand
• QR code login: Generates QR → polls scan status → auto-extracts SESSDATA from response headers
• Offline download + LAN sharing: Background multi-quality download + built-in HTTP server for LAN QR sharing

Tech stack: React Native 0.83 + Expo SDK 55 + expo-router v4 + Zustand + react-native-video + TypeScript

Checklist

• Added to the correct section (Open Source Apps)
• Format follows [Name](url) - Description.
• Description ends with a period
• No duplicate entry exists
• Open source (MIT license)