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/routes/apps/deploy.js

@@ -420,10 +420,11 @@ module.exports = function({ docker, caddy, credentialManager, servicesStateManag
 
       res.json(response);
     } catch (error) {
-      await logError('app-deploy', error, { appId, config });
-      log.error('deploy', 'Deployment failed', { appId, error: error.message });
+      try { await logError('app-deploy', error, { appId, config }); } catch (_) { /* logError failure should not mask original error */ }
+      const msg = error?.message || String(error || 'Unknown error');
+      log.error('deploy', 'Deployment failed', { appId, error: msg });
       const template = ctx.APP_TEMPLATES[appId];
-      ctx.notification.send('deploymentFailed', 'Deployment Failed', `Failed to deploy **${template?.name || appId}**.\nError: ${error.message}`, 'error');
+      try { ctx.notification.send('deploymentFailed', 'Deployment Failed', `Failed to deploy **${template?.name || appId}**.\nError: ${msg}`, 'error'); } catch (_) {}
       errorResponse(res, 500, ctx.safeErrorMessage(error));
     }
   }, 'apps-deploy'));

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