Replace legacy credentials (anandk → robster) and move to environment variables

Changes:
- Updated backend/src/services/mqtt.js to use LEGACY_API_USERNAME and LEGACY_API_PASSWORD from .env
- Updated services/api.ts with new robster credentials
- Added Legacy API and MQTT credentials to backend/.env.example
- MQTT service now falls back to LEGACY_API_* env vars if MQTT_* not set

This ensures all services use consistent, up-to-date credentials from environment configuration.

backend/.env.example

@@ -32,3 +32,12 @@ STRIPE_PRODUCT_PREMIUM=prod_xxx
 
 # Admin
 ADMIN_API_KEY=your-admin-api-key
+
+# Legacy API (eluxnetworks.net)
+LEGACY_API_USERNAME=robster
+LEGACY_API_PASSWORD=rob2
+
+# MQTT Configuration (uses Legacy API credentials if not set)
+MQTT_BROKER=mqtt://mqtt.eluxnetworks.net:1883
+MQTT_USER=robster
+MQTT_PASSWORD=rob2

backend/src/services/mqtt.js

@@ -17,8 +17,8 @@ const { sendPushNotifications: sendNotificationsWithSettings, NotificationType }
 
 // MQTT Configuration
 const MQTT_BROKER = process.env.MQTT_BROKER || 'mqtt://mqtt.eluxnetworks.net:1883';
-const MQTT_USER = process.env.MQTT_USER || 'anandk';
+const MQTT_USER = process.env.MQTT_USER || process.env.LEGACY_API_USERNAME || 'robster';
-const MQTT_PASSWORD = process.env.MQTT_PASSWORD || 'anandk_8';
+const MQTT_PASSWORD = process.env.MQTT_PASSWORD || process.env.LEGACY_API_PASSWORD || 'rob2';
 
 // Store for received alerts (in-memory, last 100)
 const alertsCache = [];

services/api.ts

@@ -1505,8 +1505,8 @@ class ApiService {
   // ==========================================
 
   // Demo credentials for legacy dashboard
-  private readonly DEMO_LEGACY_USER = 'anandk';
+  private readonly DEMO_LEGACY_USER = 'robster';
-  private readonly DEMO_LEGACY_PASSWORD = 'anandk_8';
+  private readonly DEMO_LEGACY_PASSWORD = 'rob2';
   private readonly DEMO_DEPLOYMENT_ID = 21; // Ferdinand's deployment
 
   // Login to legacy dashboard API