Migrate Oxfmt

This walks you through switching from Prettier or Biome to Oxfmt, a faster formatter that's mostly Prettier-compatible. It runs an automated migration command that converts your config file and ignore patterns, then explains what to review afterward. The main gotchas are printWidth defaults (80 vs 100), overrides that need manual conversion, and a few experimental Prettier features that don't work yet. It also covers oxfmt-specific extensions like import sorting and Tailwind class ordering. Useful if you want the speed bump without rewriting all your formatting rules by hand, though you'll still need to spot-check the output and handle edge cases yourself.