fix(docs): fix Cypress CI timeout by removing --open flag and increasing wait-on timeout

The preview command included --open which tries to launch a browser,
causing issues in headless CI. Also increased wait-on timeout from 15s
to 60s to accommodate slower CI environments.

https://claude.ai/code/session_012Jk2EZg5RhCkfrE72GcREQ

Author: claude

docs/scripts/test-cypress

@@ -5,10 +5,10 @@ set -e
 cd "$(dirname "$0")/.."
 
 echo '== Starting server =='
-pnpm run preview &
+pnpm exec iles preview --port 3050 &
 
 echo '== Waiting for server to respond... =='
-pnpx wait-on http-get://localhost:3050 --delay 1000 --timeout 15000
+pnpx wait-on http-get://localhost:3050 --delay 1000 --timeout 60000
 
 echo '== Server ready! =='