On resize the renderer is recreated with a fresh TypefaceFontProvider.
loadFont() had an early return for cached fonts that skipped registering
with the new provider, so ParagraphBuilder had no fonts to render with.
- Font service (src/engine/fonts.ts) loads system fonts on demand
- Same font bytes registered in both CanvasKit and browser (FontFace API)
- Eliminates rendering mismatch between canvas and text editing overlay
- queryLocalFonts() for enumeration and blob() for font data
- Bundled Inter-Regular.ttf as fallback when API unavailable
- Renderer uses font service instead of hardcoded fetch
