Upgrade Calcit and add verified COS deployment

[tiye]

Summary

• upgrade Calcit and @calcit/procs to 0.27.0 with current pinned Respo modules
• update Yarn to 4.18.0 and Vite to 8.3.1
• build with repository-scoped CDN URLs
• upload through cos-upload-action v1.1.1 with built-in public verification
• retain main-only rsync deployment

Verification

• strict workflow verification passes
• public definitions: 29/29
• deprecated API usage: 0
• dynamic method dispatch: 0
• immutable Yarn install and Caps toolchain verification pass
• PR build references https://cos-sh.tiye.me/Memkits/markdown-editor/pr/