🔧 Remove coverage in clean target

clean only wiped dist, leaving the gitignored coverage/ tree to
accumulate across runs. Remove both so a clean checkout state is
actually reachable.

package.json

@@ -45,7 +45,7 @@
         "check:oxfmt": "oxfmt --check ${LEFTHOOK_FILES:-.}",
         "check:oxlint": "oxlint ${LEFTHOOK_FILES:-src}",
         "check:tsc": "tsc",
-        "clean": "node -e \"fs.rmSync('dist', { recursive: true, force: true })\"",
+        "clean": "node -e \"for (const d of ['dist', 'coverage']) fs.rmSync(d, { recursive: true, force: true })\"",
         "fix": "npm run fix:oxlint && npm run fix:oxfmt",
         "fix:oxfmt": "oxfmt ${LEFTHOOK_FILES:-.}",
         "fix:oxlint": "oxlint --fix src",