Provide font on app side - breaking change

[SamuelBrucksch]

With this PR we remove the provided Material Symbol Font and let the app set the default font.

Setup

1. Add a .ttf font file to your native projects:

   • iOS — add <name>.ttf to your app bundle (no UIAppFonts entry needed — the library registers it via CoreText automatically).
   • Android — place <name>.ttf in res/font/.

   For cross-platform compatibility use lowercase names with underscores only (e.g. material_symbols).

2. Register the font and an optional glyph map at startup:

   import { setIconFont } from '@iternio/react-native-auto-play';
   import { glyphMap } from './assets/Glyphmap';
   
   setIconFont('material_symbols', glyphMap);

3. Use glyph images by name or code point:

   { type: 'glyph', name: 'directions_car' }
   { type: 'glyph', codepoint: 0xe531 }

setIconFont must be called once before the first glyph is used (subsequent calls are ignored). If no font is registered, the library throws an error when a glyph image is rendered.

Type-safe glyph names

To get autocompletion and type checking for glyph names, create a declaration file in your app (e.g. autoplay-glyphs.d.ts):

import type { GlyphName } from './assets/Glyphmap';

declare module '@iternio/react-native-auto-play' {
  interface AutoPlayGlyphMap extends Record<GlyphName, number> {}
}

Without this augmentation, name accepts any string. With it, only keys from your glyph map are allowed and you get full autocompletion.

[github-actions]

The mutable static variable cachedFontName is not protected against concurrent access, which may lead to thread-safety issues.

[SamuelBrucksch]

Not sure this is actually an issue...

[github-actions]

The mutable static variable cachedPSName is not protected against concurrent access, which may lead to thread-safety issues.

[github-actions]

Minor thread-safety concerns were identified regarding the mutable global cached state in the native modules.