chore(release): prepare v1.0.0 release

[dipto0321]

Phase 8: v1.0.0 release

Pre-release checklist from docs/release-checklist.md:

• All planned issues/PRs for this version merged to main
• CHANGELOG.md regenerated from conventional commits
• README install instructions verified against actual artifacts
• All docs reviewed for accuracy
• make ci green locally
• Cross-platform smoke test (macOS, Linux, Windows)
• Manual upgrade flow tested on at least one platform

Tagging and release:

git checkout main
git pull
git tag -a v1.0.0 -m "Release v1.0.0"
git push origin v1.0.0

This triggers .github/workflows/release.yml which:

• Creates GitHub Release with binaries + checksums
• Pushes Homebrew formula to dipto0321/homebrew-tap
• Pushes Scoop manifest to dipto0321/scoop-bucket
• Publishes npm wrapper

See .puku/plans/nodeup_v1_build_plan_3481ccad.plan.md Phase 8 and docs/release-checklist.md.