fix: harden deploy error handling - guard against undefined errors, safeErrorMessage null check

- deploy.js: wrap logError/notification in try/catch so they never mask the original deploy error
- deploy.js: use optional chaining for error.message access
- logging.js: safeErrorMessage handles null/undefined error gracefully

dashcaddy-api/src/utils/logging.js

@@ -94,6 +94,7 @@ async function logError(ERROR_LOG_FILE, MAX_ERROR_LOG_SIZE, context, error, addi
  * Return a safe error message without leaking internals
  */
 function safeErrorMessage(error) {
+  if (!error) return 'An internal error occurred';
   const msg = error.message || String(error);
 
   // Detect port conflict errors