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/pages/admin/AdminRuns.tsx

@@ -16,19 +16,28 @@ export function AdminRuns() {
 
   const gameMap = useMemo(
     () => new Map(games.map((g) => [g.id, g.name])),
-    [games],
+    [games]
   )
 
   const filteredRuns = useMemo(() => {
     let result = runs
     if (statusFilter) result = result.filter((r) => r.status === statusFilter)
-    if (gameFilter) result = result.filter((r) => r.gameId === Number(gameFilter))
+    if (gameFilter)
+      result = result.filter((r) => r.gameId === Number(gameFilter))
     return result
   }, [runs, statusFilter, gameFilter])
 
   const runGames = useMemo(
-    () => [...new Map(runs.map((r) => [r.gameId, gameMap.get(r.gameId) ?? `Game #${r.gameId}`])).entries()].sort((a, b) => a[1].localeCompare(b[1])),
-    [runs, gameMap],
+    () =>
+      [
+        ...new Map(
+          runs.map((r) => [
+            r.gameId,
+            gameMap.get(r.gameId) ?? `Game #${r.gameId}`,
+          ])
+        ).entries(),
+      ].sort((a, b) => a[1].localeCompare(b[1])),
+    [runs, gameMap]
   )
 
   const columns: Column<NuzlockeRun>[] = [
@@ -86,12 +95,17 @@ export function AdminRuns() {
         >
           <option value="">All games</option>
           {runGames.map(([id, name]) => (
-            <option key={id} value={id}>{name}</option>
+            <option key={id} value={id}>
+              {name}
+            </option>
           ))}
         </select>
         {(statusFilter || gameFilter) && (
           <button
-            onClick={() => { setStatusFilter(''); setGameFilter('') }}
+            onClick={() => {
+              setStatusFilter('')
+              setGameFilter('')
+            }}
             className="text-sm text-gray-500 hover:text-gray-700 dark:text-gray-400 dark:hover:text-gray-200"
           >
             Clear filters
@@ -120,7 +134,10 @@ export function AdminRuns() {
               onSuccess: () => setDeleting(null),
             })
           }
-          onCancel={() => { setDeleting(null); deleteRun.reset() }}
+          onCancel={() => {
+            setDeleting(null)
+            deleteRun.reset()
+          }}
           isDeleting={deleteRun.isPending}
           error={deleteRun.error?.message ?? null}
         />