feat: bare npm name — interscript@3.0.0

[ronaldtse]

Summary

• publish the TS runtime under the org's bare npm name: interscript@3.0.0, superseding the legacy interscript-js 2.4.x line (which gets a deprecation notice pointing here)
• matches the registry strategy of the Ruby gem (interscript on RubyGems) and the secryst family (bare name per registry); the major version signals the implementation break

Test plan

• build + 242 tests green, format clean
• after merge: deprecate legacy npm versions (<3.0.0), link npm Trusted Publisher for interscript (this repo + release.yml), tag v3.0.0 publishes