* fix(text): request script fallbacks for substituted text
When a text's font could not be loaded and the default family
substituted for it, font readiness returned before checking glyph
coverage. That check is what requests CJK and Arabic fallbacks, so text
such as Chinese in an unavailable PingFang SC drew missing glyphs unless
another layer happened to request the fallback first.
Substituted text now observes glyph coverage too. It waits while a
fallback loads and stays visible when none is available.
* fix(fonts): explain installed fonts with unsupported outlines
On macOS 15 and later PingFang ships only `hvgl` outlines, which neither
font-kit nor CanvasKit can read. The desktop loader spent over a second
parsing the collection per style, and the font banner showed PingFang as
substituted with no explanation.
The loader now reads the family's table directories first and returns a
structured unsupported-format error. The font manager records it per
face, document font status exposes it as `reason`, and the banner shows
it inline with the full explanation in a tooltip. The resolver reports
progress after each failed candidate so the banner updates before web
font lookups finish.
* fix(fonts): keep the unsupported-format reason after failed retries
A later host attempt that returns no font no longer clears the reason; only a loaded face does.
- Track loaded font provenance and aggregate page-level face fidelity, including synthesized styles and active Inter substitutions
- Add a localized warning banner with retry and affected-layer actions
- Expose get_font_status through the Figma API and MCP tool registry
- Gate ingest rendering until required faces and script fallbacks resolve
- Key CanvasKit artifacts by font registration generation and invalidate affected nodes
- Load character-aware remote subsets with cumulative coverage and exact render aliases
- Use BCP-47 language hints for shaping and CJK fallback order
- Keep baked .fig glyphs as an exhaustion-only fallback
- Resolve exact faces through registered, local, cache, and remote sources with deduplicated state transitions\n- Use CanvasKit notdef glyphs to request script fallbacks and repaint after resolution\n- Make CJK coverage analysis codepoint-safe across supplementary characters and style runs
