chore: use public repository URL

[snkk2x-collab]

Summary

• update the package repository metadata from an SSH GitHub URL to a public HTTPS Git URL
• make the npm package metadata easier for package registries and tooling to consume without GitHub SSH access

Validation

• node -e metadata assertion
• git diff --check
• pnpm --package=yarn@1.22.22 dlx yarn install --frozen-lockfile --ignore-scripts
• pnpm --package=yarn@1.22.22 dlx yarn test (1 suite / 4 tests passed)
• pnpm --package=yarn@1.22.22 dlx yarn lint
• pnpm --package=yarn@1.22.22 dlx yarn pack --dry-run

Notes:

• Yarn install reports existing old peer dependency warnings from eslint-config-mailonline and eslint-import-resolver-webpack.
• Node 24 reports deprecation warnings from old transitive dependencies during install/test.
• Yarn v1 writes a tarball even with --dry-run; I removed the generated tarball before committing.