fix(autoHeightBridge): rewrite bridge to stateful, idempotent implementation with improved measurement and observers

- introduce GLOBAL_KEY state to prevent duplicate injections and expose refresh/destroy
- more robust height measurement (getBoundingClientRect + scroll/offset/client sizes)
- adaptive debouncing (active/idle), microtask scheduling and fallback timers for stability
- track media (img/iframe/video) loads, observe mutations/resizes/fonts/viewport, and ensure cleanup
- use safe event registration and postMessage compatibility with ReactNativeWebView

Author: mCodex