Initial sync of shared/playground-design-system/ into
plugins/ms-ai-architect/playground/vendor/playground-design-system/
via scripts/sync-design-system.mjs.
Source commit: f1fecf39b8
Files: 25 (7 CSS + 11 fonts/licenses + 3 schemas + README + MANIFEST)
Vendored copy keeps the plugin standalone — playground will load CSS
from ./vendor/ regardless of where the plugin is installed.
Also adds .gitleaks.toml at repo root with a path allowlist for
vendored MANIFEST.json files (SHA-256 file hashes are not secrets).
Docs updated together with the playground HTML refactor that actually
consumes the vendored CSS (next commit). This commit is internal-only.
