Upgrade to Calcit 0.27 and publish assets through COS

[tiye]

Summary

• upgrade Calcit, @calcit/procs, Caps dependencies, and Yarn for the current toolchain
• migrate client/server code to strict Calcit 0.27 schemas, Option/Result semantics, and explicit FFI boundaries
• build with repository-scoped absolute COS URLs for PR, main, and branch runs
• upload to COS and verify public CDN assets before main-only rsync deployment
• pin Actions by immutable commit SHA and remove the obsolete compatibility baseline

Verification

• strict workflow verification passes with no pending fixes
• client check: 246/246
• server check: 52/52
• deprecated calls: 0
• dynamic method findings: 0
• Node 24 / Vite 8 production build passes
• local CDN reference verifier passes for https://cos-sh.tiye.me/TopixIM/timedrops/pr/
• server IR compilation passes