fix: Add polling mechanism for sensor threshold monitoring

Problem:
- Firebase SDK listener not triggering (SDK timeout)
- No sensor data being checked despite sensor=true
- Log shows no SENSOR CHECK output

Solution:
- Add polling every 30 seconds using REST API (reliable)
- Keep Firebase listener as backup if SDK recovers
- Check kontrolConfig.sensor flag before processing
- Shared checkSensorThresholds() function for both methods

This ensures sensor mode works even when Firebase SDK fails

worker.js

@@ -786,28 +786,32 @@ setTimeout(async () => {
 
 let sensorCheckCounter = 0;
 
-async function setupSensorMonitoring() {
-  console.log('🌡️  ==================== SENSOR MODE ENABLED ====================');
-  console.log('✅ Sensor Mode (Threshold System) monitoring started');
-  console.log('📍 Listening to Firebase path: /data');
-  console.log('📍 Config path: /' + FIREBASE_PATHS.kontrol);
-  console.log('⏱️  Debounce time: 2 minutes between watering per pot');
-  console.log('================================================================\n');
-
-  db.ref('data').on('value', async (snapshot) => {
+// Core sensor check logic (shared by listener and polling)
+async function checkSensorThresholds() {
   sensorCheckCounter++;
   
   try {
-      const sensorData = snapshot.val();
+    // Fetch sensor data using smart method (REST fallback)
+    const sensorData = await readFirebaseSmart('data');
+    
     if (!sensorData) {
-        console.log('⚠️  Sensor data is null/empty');
+      console.log('⚠️  Sensor data is null/empty - ESP32 might not be sending data');
       return;
     }
 
-      const configSnapshot = await fetchWithTimeout(db.ref(FIREBASE_PATHS.kontrol), 10000);
-      const kontrolConfig = configSnapshot.val();
+    // Fetch kontrol config using smart method
+    const kontrolConfig = await fetchKontrolSmart();
 
     if (!kontrolConfig) {
+      console.log('⚠️  Kontrol config is null');
+      return;
+    }
+    
+    // Check if sensor mode is enabled
+    if (!kontrolConfig.sensor) {
+      if (sensorCheckCounter % 10 === 0) {
+        console.log(`⚠️  Sensor mode DISABLED (sensor=false). Skipping threshold check.`);
+      }
       return;
     }
 
@@ -908,9 +912,54 @@ async function setupSensorMonitoring() {
       }
     }
   } catch (error) {
-      console.error('❌ Error in threshold monitoring:', error.message);
+    console.error('❌ Error in sensor threshold check:', error.message);
   }
+}
+
+// Setup sensor monitoring with BOTH listener (SDK) and polling (fallback)
+async function setupSensorMonitoring() {
+  console.log('🌡️  ==================== SENSOR MODE ENABLED ====================');
+  console.log('✅ Sensor Mode (Threshold System) monitoring started');
+  console.log('📍 Primary: Polling every 30 seconds (REST API)');
+  console.log('📍 Backup: Firebase listener on /data (if SDK works)');
+  console.log('📍 Config path: /' + FIREBASE_PATHS.kontrol);
+  console.log('⏱️  Debounce time: 2 minutes between watering per pot');
+  console.log('================================================================\n');
+
+  // METHOD 1: Polling (RELIABLE - uses REST API)
+  // Check sensor threshold every 30 seconds
+  setInterval(async () => {
+    try {
+      await checkSensorThresholds();
+    } catch (error) {
+      console.error('❌ Polling sensor check failed:', error.message);
+    }
+  }, 30000); // 30 seconds
+
+  // Run first check immediately
+  setTimeout(async () => {
+    console.log('🚀 Running first sensor check...');
+    try {
+      await checkSensorThresholds();
+      console.log('✅ First sensor check completed');
+    } catch (error) {
+      console.error('❌ First sensor check failed:', error.message);
+    }
+  }, 10000); // 10 seconds after startup
+
+  // METHOD 2: Firebase Listener (BACKUP - might not work if SDK fails)
+  try {
+    db.ref('data').on('value', async (snapshot) => {
+      console.log('🔔 Firebase listener triggered (SDK working!)');
+      // Call the same check function
+      await checkSensorThresholds();
+    }, (error) => {
+      console.error('❌ Firebase listener error:', error.message);
     });
+    console.log('✅ Firebase listener attached (backup method)');
+  } catch (error) {
+    console.log('⚠️  Firebase listener failed to attach (will rely on polling)');
+  }
 }
 
 setupSensorMonitoring();