fix: use npm install instead of npm ci for Playwright setup

npm ci requires package-lock.json which doesn't exist in root directory

Author: claude

.github/workflows/ui-tests.yml

@@ -127,7 +127,7 @@ jobs:
 
       - name: Install Playwright
         run: |
-          npm ci
+          npm install
           npx playwright install --with-deps chromium
 
       - name: Run Playwright Tests