feat: release ContentCloud v0.13.0

[wutongci]

Summary

• unify the product brand as Content Work OS across marketing, workspace, admin, auth, docs, and public review surfaces
• add shared BrandMark and BrandLockup components with a refreshed favicon and design system
• publish synchronized v0.13.0 CLI, Web, npm, Plugin, MCP, Bootstrap, and environment metadata

Verification

• node scripts/evaluate-plugin.mjs (12 scenarios)
• node scripts/validate-plugin-release.mjs
• node --check packages/contentcloud/bin/contentcloud.js
• pnpm install --frozen-lockfile
• make check
• go test -race ./...
• pnpm --dir web test (14 files, 64 tests)