Closes the deferred font tag from the Tier-3 plan. Wire-up:
* quartz: FontTag(family, optionalUrl) parser/assembler with
blank-rejection on family + blank-URL-becomes-null normalisation.
* MeetingSpaceEvent.font(): FontTag? accessor.
* TagArrayBuilder.font(family, url) DSL.
* RoomTheme gains fontFamily / fontUrl fields.
* AudioRoomThemedScope maps `family` to a Compose FontFamily for
the four CSS-style generic-family names ("sans-serif", "serif",
"monospace", "cursive") — each maps to the corresponding system
fallback. The whole Material3 typography is rebuilt with that
family so headlines / body / labels all swap together.
URL-based font loading (RoomTheme.fontUrl) is the natural follow-up:
fetch + cache via OkHttp, then build a FontFamily from a local
file. Until then, an unknown family is silently a no-op — the room
renders in the platform default rather than crashing or fetching
on the UI thread.
Tests:
* FontTagTest — 9 cases covering family-only, family+URL,
blank rejection, missing family, wrong tag name, blank-URL
normalisation, assembler shapes (with + without URL), and
the assembler's blank-family rejection.
* RoomThemeTest gains 3 cases for font projection (family-only /
family+URL / empty event).
Claude
14863415d5