chore(tokens): expose v2 migration bin

[netchampfaris]

Summary

• expose the espresso v2 token migration codemod as the tokens-v2 package bin
• add a shebang, help output, and symlink-safe CLI detection for package-manager execution

Testing

• node tailwind/migrate-tokens-v2.js --help
• npm pkg get bin

Coverage: 56.48% (±0.00% vs main)

Docs preview: https://ui.frappe.io/pr-preview/pr-775/

[barista-for-frappe]

Looks good — exposes the v2 token codemod as the tokens-v2 bin; pure tooling, no component API surface.

• tailwind/migrate-tokens-v2.js:401 — resolving symlinks on both sides is the right call: the old path.resolve wouldn't follow the package-manager bin symlink, so isCLI would never fire when run as tokens-v2.
• Minor: fs.realpathSync(invokedPath) throws if process.argv[1] isn't a real on-disk path (some loaders). The invokedPath && guard covers the undefined case but not a non-existent path. Edge-case only; wrap in try/catch if you want to be safe.