fix: replace manual oxfmt shell script with lint-staged

The pre-commit hook used a manual shell script to format staged files,
but `2>/dev/null || true` swallowed errors silently. When oxfmt failed,
unformatted code was committed and only caught later by the pre-push
`oxfmt --check`, blocking pushes with pre-existing formatting drift.

Switch to lint-staged (the official oxfmt recommendation) which handles
staged file filtering, formatting, and re-staging correctly — including
partial staging.

Author: petekp

.githooks/pre-commit

@@ -3,12 +3,4 @@ set -eu
 
 pnpm hooks:pre-commit
 
-# Auto-fix formatting on staged files and re-stage them
-STAGED=$(git diff --cached --name-only --diff-filter=ACMR)
-if [ -n "$STAGED" ]; then
-  WWW_STAGED=$(echo "$STAGED" | grep '^apps/www/' || true)
-  if [ -n "$WWW_STAGED" ]; then
-    echo "$WWW_STAGED" | sed 's|^apps/www/||' | (cd apps/www && xargs oxfmt 2>/dev/null) || true
-    echo "$WWW_STAGED" | xargs git add
-  fi
-fi
+pnpm lint-staged

package.json

@@ -34,11 +34,15 @@
   },
   "devDependencies": {
     "@changesets/cli": "^2.29.8",
+    "lint-staged": "^16.4.0",
     "tsx": "^4.21.0"
   },
   "engines": {
     "node": ">=20",
     "pnpm": ">=8.0.0"
   },
+  "lint-staged": {
+    "apps/www/**/*.{ts,tsx,js,jsx,mjs,cjs,css,json,jsonc}": "oxfmt --no-error-on-unmatched-pattern"
+  },
   "packageManager": "pnpm@10.11.0"
 }