Add --access public to npm publish

[anth-volk]

Fixes #7

Summary

• Add --access public flag to npm publish in CI workflow for scoped package first publish

Test plan

• Verified locally with npm publish --access public --dry-run — passes
• Merge and confirm CI publishes @policyengine/ui-kit to npm successfully

🤖 Generated with Claude Code

[policyengine]

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