feat: UX improvements — secure webhooks, locale fixes, dynamic languages, UI polish

- Remove top paginator from dashboard events, keep only bottom
- Fix test message locale: pass UI locale to email/matrix bot tests
- Convert webhook auth mode from text input to icon grid selector
- Generate secure UUID tokens for webhook URLs instead of sequential IDs
- Move Recent Payloads into per-provider expandable container (lazy-loaded)
- Make template config languages dynamic via app settings instead of hardcoded
- Change default dev port to 5175

scripts/restart-frontend.sh

@@ -6,7 +6,7 @@ set -e
 cd "$(dirname "$0")/.."
 
 # Kill existing frontend
-PID=$(netstat -ano 2>/dev/null | grep ':5173.*LISTENING' | awk '{print $5}' | head -1)
+PID=$(netstat -ano 2>/dev/null | grep ':5175.*LISTENING' | awk '{print $5}' | head -1)
 if [ -n "$PID" ]; then
   taskkill //F //PID "$PID" 2>/dev/null || true
   sleep 1
@@ -14,8 +14,8 @@ fi
 
 # Start frontend
 cd frontend
-npx vite dev --port 5173 --host > /dev/null 2>&1 &
+npx vite dev --port 5175 --host > /dev/null 2>&1 &
 cd ..
 
 sleep 4
-curl -s -o /dev/null -w "Frontend: %{http_code}\n" http://localhost:5173/
+curl -s -o /dev/null -w "Frontend: %{http_code}\n" http://localhost:5175/