fix: use latest published npm version for bumping to prevent duplicates

[ryanande]

Fixes the duplicate version error by checking npm for the latest published version before bumping.

Problem:

• Workflow was bumping from package.json (1.1.0) instead of latest published (1.1.1)
• This caused duplicate version errors when trying to publish

Solution:

• ✅ Check npm for latest published version first
• ✅ Bump from published version (e.g., 1.1.1 → 1.1.2)
• ✅ Fall back to package.json if package not published yet
• ✅ Removed duplicate checkout step

Also includes:

• README improvements (better examples, TypeScript docs, use cases)

This ensures the workflow always bumps from the correct version source.