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-backend.sh

@@ -11,14 +11,15 @@ if [ -n "$PID" ]; then
   sleep 1
 fi
 
-# Resolve python — py launcher needs absolute path for nohup on Windows
-if command -v python3 &>/dev/null; then
+# Resolve python — prefer py launcher on Windows (python3 may be the Store stub)
+if command -v py &>/dev/null; then
+  PYTHON=$(py -3 -c "import sys; print(sys.executable)" 2>/dev/null)
+elif command -v python3 &>/dev/null && python3 --version &>/dev/null; then
   PYTHON=python3
-elif command -v python &>/dev/null; then
+elif command -v python &>/dev/null && python --version &>/dev/null; then
   PYTHON=python
 else
-  PYTHON=$(py -3.13 -c "import sys; print(sys.executable)" 2>/dev/null \
-        || py -3 -c "import sys; print(sys.executable)")
+  echo "Python not found"; exit 1
 fi
 
 # Start backend