Relicense ArtCraft under MIT OR Apache-2.0 (#2043)

## Summary
- Removes the WIP fair-source `LICENSE.md` and adds `LICENSE-MIT` and
`LICENSE-APACHE`, matching PhotoCraft, LightCraft, and the other craft
apps.
- Adds `NOTICE`, which lists bundled third-party material (ammo.js, the
vendored tauri-plugin-http, normalize.css, three-dots, Font Awesome
icons, the Carter One font) and says that provider logos are trademarks
of their owners.
- Updates the README's License section, and sets `license` in
`crates/desktop/artcraft/Cargo.toml` and `frontend/package.json` to `MIT
OR Apache-2.0`.

## Follow-up needed
`NOTICE` excludes assets that ArtCraft doesn't own: Nintendo sound
effects in `resources/sound/`, meme images, the AllSky-style gray/night
skyboxes, the Lumine VMD, and the Mixamo animation GIFs. The exclusion
only says these files aren't MIT/Apache. They still need to be replaced
or removed in a separate PR. Nobody has confirmed where the avatars,
default covers, `characters/img*.png`, and the day skybox came from.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -136,4 +136,10 @@ Additional provider integrations are planned for Kling, Google, Runway, and Luma
 - [Developer documentation](./_docs)
 - [Desktop build and development scripts](./script/artcraft)
 - [Roadmap](./ROADMAP.md)
-- [License](./LICENSE.md)
+- [License](#license)
+
+## License
+
+ArtCraft is dual-licensed under [MIT](LICENSE-MIT) or [Apache-2.0](LICENSE-APACHE), at your option.
+Copyright (c) 2026 ArtCraft Team and the ArtCraft contributors. Required notices, including
+third-party material not covered by this license, are in [NOTICE](NOTICE).