feat: automate compatibility and schema distribution

[OgeonX-Ai]

Summary

• classify pull-request schema changes against the latest semantic release
• build and validate deterministic stable and immutable schema registry artifacts
• publish released schemas through GitHub Pages with GSD Phase 2 verification

Validation

• npm test (13/13)
• npm run validate
• npm run build:registry -- --version 0.1.0
• npm run validate:registry -- --registry registry
• yamllint on new workflows
• compatibility comparison against archived v0.1.0: unchanged

[chatgpt-codex-connector]

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