refactor(theme): unify frontend color token governance

[GCWing]

Summary

• make @bitfun/design-tokens and @bitfun/theme-bitfun the canonical color source for ordinary frontend UI
• move Web UI Appearance to schema v2 theme-tokens, retain one-way v1 package migration, and remove runtime compatibility projections
• migrate Web UI, Design Lab, Website, Markets, Mobile Web, Installer, native mobile, Desktop bootstrap, widgets, and MiniApps to governed semantic/domain tokens
• add registry-driven cross-surface color audits plus deterministic Desktop, MiniApp, native-mobile, and relay/static projections

Validation

• pnpm run check:web
• pnpm run design-system:check
• pnpm run mobile:ui:check
• pnpm run mobile:architecture
• pnpm --dir BitFun-Installer run build
• pnpm --dir src/mobile-web run type-check
• pnpm run build:mobile-web
• MiniApp Market: type-check, 17 tests, production build
• Skin Market: type-check, 27 tests, production build
• Website: 8 tests and production build
• cargo check -p bitfun-desktop
• git diff --check origin/1.0.0-explore...HEAD

Validation boundaries

• pnpm run harmony:architecture reports two local false positives because its exact text assertions use LF while this Windows checkout uses CRLF; the required reuse and observable-row source contracts are present. Linux CI is authoritative for this gate.
• Browser-controlled, Mock, native E2E, and manual visual verification were not run, following repository guidance.
• Android, iOS, and HarmonyOS device builds were not run on this Windows host; generated native contracts are in sync and the cross-platform mobile architecture check passed.
• Remote workspace, Remote Control, Peer Device Mode, and Detached Dispatch were not exercised separately; this PR changes shared appearance contracts and static projections, not transport or runtime behavior.

AI-assisted change; validation level is recorded above.