style: format the repository with prettier

These files were already out of step with the project's Prettier config
before this branch of work; running `pnpm format` finally swept them up.
No semantic changes.

Kept separate from the functional commits so the reformatting does not
bury them in diff noise.

postcss.config.mjs

@@ -2,4 +2,4 @@ export default {
   plugins: {
     "@tailwindcss/postcss": {},
   },
-};
+}