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/TransferModal.tsx

@@ -8,9 +8,14 @@ interface TransferModalProps {
   isPending: boolean
 }
 
-export function TransferModal({ hofTeam, onSubmit, onSkip, isPending }: TransferModalProps) {
+export function TransferModal({
+  hofTeam,
+  onSubmit,
+  onSkip,
+  isPending,
+}: TransferModalProps) {
   const [selected, setSelected] = useState<Set<number>>(
-    () => new Set(hofTeam.map((e) => e.id)),
+    () => new Set(hofTeam.map((e) => e.id))
   )
 
   const toggle = (id: number) => {
@@ -34,7 +39,8 @@ export function TransferModal({ hofTeam, onSubmit, onSkip, isPending }: Transfer
             Transfer Pokemon to Next Leg
           </h2>
           <p className="text-sm text-gray-500 dark:text-gray-400 mt-1">
-            Selected Pokemon will be bred down to their base form and appear as level 1 encounters in the next leg.
+            Selected Pokemon will be bred down to their base form and appear as
+            level 1 encounters in the next leg.
           </p>
         </div>