Function useHostFonts

useHostFonts(app: App | null, initialContext?: McpUiHostContext | null): void
React hook that applies host fonts from CSS.

This hook listens to host context changes and automatically applies:
- styles.css.fonts as a <style> tag for custom fonts
The CSS can contain @font-face rules for self-hosted fonts, @import statements for Google Fonts or other font services, or both.

The hook also applies fonts from the initial host context when the app first connects.
Parameters
- app: App | null
  The connected App instance, or null during initialization
- OptionalinitialContext: McpUiHostContext | null
  Initial host context from the connection (optional). If provided, fonts will be applied immediately on mount.
Returns void
Example: Basic usage with useApp
```
function MyApp() {
  const { app } = useApp({
    appInfo: { name: "MyApp", version: "1.0.0" },
    capabilities: {},
  });

  // Apply host fonts - pass initial context to apply fonts from connect() immediately
  useHostFonts(app, app?.getHostContext());

  return <div style={{ fontFamily: "var(--font-sans)" }}>Hello!</div>;
}
```
See
- applyHostFonts for the underlying fonts function
- useHostStyleVariables for applying style variables and theme
- Defined in src/react/useHostStyles.ts:125