Panel resizing now creates a new surface from the existing
GrDirectContext instead of destroying and recreating the entire
renderer. All caches (paints, fonts, node pictures, scene picture,
filters) are preserved across resizes.
- 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
- Skip rendering text node on canvas while textarea overlay is active
- Skip selection handles for the node being edited
- Remove border from textarea (was causing double outline)
- Add @font-face for Inter-Regular.ttf so textarea matches CanvasKit
