fix(cache): reduce Valkey connectTimeout to 1.5s to avoid 10s hang

When Valkey is unreachable, ioredis was holding cache.get() calls in
the offline queue for the default 10s connectTimeout before failing.
This caused admin/image-gen and text-gen pages to stall on every load.

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

ui/src/lib/server/cache.ts

@@ -20,7 +20,8 @@ function client(): Redis {
 		_client = new Redis(url, {
 			lazyConnect: false,
 			enableOfflineQueue: true,
-			maxRetriesPerRequest: 2
+			maxRetriesPerRequest: 1,
+			connectTimeout: 1500
 		});
 		_client.on('error', (err: Error) => {
 			console.error('[cache] Valkey error:', err.message);