Add LICENSE-MIT and LICENSE-APACHE (Copyright (c) 2026 ArtCraft Team and the
LightCraft contributors) and docs/brand/LICENSE-brand.txt from the Crafting Apps
licensing standard. Rewrite NOTICE to the standard template and drop the stale
Source Sans 3 entry (only Inter is bundled). Attribute docs/brand/ in
assets/ATTRIBUTION.md so `cargo xtask assets` passes again. README gets the
standard "License and credits" section; AGENTS.md/CLAUDE.md note the brand
exception to the asset rule.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>