Fonts: use craft-fonts as an optional build input; move the Japanese fonts out

Shippori Mincho (8.7 MB) and its licence leave assets/fonts. Japanese fonts now
come from storytold/craft-fonts when built with CRAFT_FONTS_DIR (never a
Cargo.toml dependency): crates/fonts/build.rs embeds its manifest as
designcraft_fonts::CRAFT_FONTS. Native builds embed all four fonts; wasm32
embeds BIZ UDPGothic Regular only (web size budget).

- UI (egui): the Jpan faces at the end of every family, BIZ UDPGothic first
  (Bold first in the semibold family).
- Documents: FontDb loads them after the bundled fonts, Mincho first, so they
  are the Japanese fallback ahead of system fonts; SVG text gets them too.
- Vertical alternates test runs on every craft-fonts face and skips when
  CRAFT_FONTS is empty; new UI no-tofu test and without-craft-fonts tests.
- FreeBSD CI tests with craft-fonts; release.yml builds every platform with
  CRAFT_FONTS_DIR + CRAFT_FONTS_REQUIRED=1 at a pinned commit, packages carry
  OFL-<family>.txt; NOTICE, ASSETS.md, AGENTS.md/CLAUDE.md, README, ROADMAP.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

AGENTS.md

@@ -21,6 +21,7 @@ People trust DesignCraft with their layouts; a crash loses their work. **This ou
 ## Non-negotiables
 - **Clean-room.** InDesign is installed on the dev machine and may be *observed* black-box: run it, use its UI with synthetic documents, take screenshots (by window id) stored only under `plan/indesign/screenshots/` (never committed). Never read, disassemble or copy anything inside the InDesign bundle (names/listings only), never copy Adobe icons, artwork, presets or wording beyond feature names, never commit files produced by InDesign. Never copy GPL/AGPL/LGPL code (Scribus, LibreOffice, Ghostscript…).
 - **Assets:** no Adobe iconography or images — ever. Every asset is original / OSI / CC0 / redistributable CC (except the ArtCraft trademarks in `docs/brand/`, under `docs/brand/LICENSE-brand.txt`) and has a row in `ASSETS.md` (`cargo xtask assets` enforces it). Prefer art generated in code.
+- **Fonts live in [`storytold/craft-fonts`](https://github.com/storytold/craft-fonts)**, never in this repo: don't commit new font files (the Latin UI/document fonts already in `assets/fonts/` stay). It is an optional build input, never a `Cargo.toml` dependency: `CRAFT_FONTS_DIR=/abs/path/to/craft-fonts cargo build` makes `crates/fonts/build.rs` embed its fonts as `designcraft_fonts::CRAFT_FONTS` (Japanese: BIZ UDPGothic for the UI, Mincho first for document text; web builds embed BIZ UDPGothic Regular only). Unset, `CRAFT_FONTS` is empty and the app uses its bundled and system fonts; code and tests must work that way (tests on its glyphs skip). Releases build with it. Standard: [craftrules `standards/fonts.md`](https://github.com/storytold/craftrules/blob/main/standards/fonts.md).
 - **Shared test corpora.** Real-file test oracles (Photoshop-authored PSDs, etc.) live in [`storytold/photocraft-corpus`](https://github.com/storytold/photocraft-corpus), explained in [craftrules `standards/test-corpora.md`](https://github.com/storytold/craftrules/blob/main/standards/test-corpora.md). Never commit large binary fixtures to this repo; fetch them pinned by commit and sha256-verified, as PhotoCraft does with `cargo xtask corpus`.
 - **Everything is a command.** User-visible behaviour = a command in `crates/engine/src/cmd/*` (id, label, menu path, shortcut, params doc, `enabled`, `run`) + tests. Tools emit commands (Begin/Preview/Commit). UI-only commands live in `crates/ui-egui/src/menus.rs` (`UI_COMMANDS`). The control channel and MCP reach all of them.
 - **Layering** is enforced by `cargo xtask layers`. Nothing below L6 depends on egui/eframe/winit/rfd. The UI crate is swappable.