chore: restore openclaw package metadata for trusted publishing

[dutifulbob]

Summary

Restore and harden release metadata so trusted publishing works out of the box.

• set author to OpenClaw Team <dev@openclaw.ai>
• set repository.url to canonical https://github.com/openclaw/acpx
• add release workflow validation that fails fast if author or repository.url drift
• run npm run build in release workflow before publish to ensure artifacts are present

Why

Recent release failed at npm publish with E422 due provenance mismatch:

• provenance repo: https://github.com/openclaw/acpx
• package metadata repo: git+https://github.com/janitrai/acpx.git

This PR fixes the mismatch and adds guardrails so it does not regress.

Validation

• npm run lint
• npm run typecheck
• npm run build
• npm test