Add pre-commit hooks for linting and formatting

Set up pre-commit framework with ruff (backend) and ESLint/Prettier/tsc
(frontend) hooks to catch issues locally before CI. Auto-format all
frontend files with Prettier to comply with the new check.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/components/admin/GameFormModal.tsx

@@ -20,13 +20,23 @@ function slugify(name: string) {
     .replace(/^-|-$/g, '')
 }
 
-export function GameFormModal({ game, onSubmit, onClose, isSubmitting, onDelete, isDeleting, detailUrl }: GameFormModalProps) {
+export function GameFormModal({
+  game,
+  onSubmit,
+  onClose,
+  isSubmitting,
+  onDelete,
+  isDeleting,
+  detailUrl,
+}: GameFormModalProps) {
   const [name, setName] = useState(game?.name ?? '')
   const [slug, setSlug] = useState(game?.slug ?? '')
   const [generation, setGeneration] = useState(String(game?.generation ?? ''))
   const [region, setRegion] = useState(game?.region ?? '')
   const [boxArtUrl, setBoxArtUrl] = useState(game?.boxArtUrl ?? '')
-  const [releaseYear, setReleaseYear] = useState(game?.releaseYear ? String(game.releaseYear) : '')
+  const [releaseYear, setReleaseYear] = useState(
+    game?.releaseYear ? String(game.releaseYear) : ''
+  )
   const [autoSlug, setAutoSlug] = useState(!game)
 
   useEffect(() => {
@@ -53,14 +63,16 @@ export function GameFormModal({ game, onSubmit, onClose, isSubmitting, onDelete,
       isSubmitting={isSubmitting}
       onDelete={onDelete}
       isDeleting={isDeleting}
-      headerExtra={detailUrl ? (
-        <Link
-          to={detailUrl}
-          className="text-sm text-blue-600 dark:text-blue-400 hover:underline"
-        >
-          View Routes & Bosses
-        </Link>
-      ) : undefined}
+      headerExtra={
+        detailUrl ? (
+          <Link
+            to={detailUrl}
+            className="text-sm text-blue-600 dark:text-blue-400 hover:underline"
+          >
+            View Routes & Bosses
+          </Link>
+        ) : undefined
+      }
     >
       <div>
         <label className="block text-sm font-medium mb-1">Name</label>