Add polling interval settings (1-30 minutes)

- Default interval: 2 minutes
- User selectable: 1, 2, 5, 10, 15, 30 minutes
- Battery/data saving with longer intervals
- Update README

app/src/main/java/com/hotdeal/alarm/presentation/main/MainViewModel.kt

@@ -105,7 +105,7 @@ class MainViewModel @Inject constructor(
         workerScheduler.executeOnce()
     }
     
-    fun startPolling(intervalMinutes: Long = 15) {
+    fun startPolling(intervalMinutes: Long = WorkerScheduler.DEFAULT_INTERVAL_MINUTES) {
         workerScheduler.schedulePeriodicPolling(intervalMinutes)
     }
     

app/src/main/java/com/hotdeal/alarm/presentation/settings/SettingsScreen.kt

@@ -28,6 +28,7 @@ import com.hotdeal.alarm.presentation.components.PermissionDialog
 import com.hotdeal.alarm.presentation.main.MainUiState
 import com.hotdeal.alarm.presentation.main.MainViewModel
 import com.hotdeal.alarm.util.PermissionHelper
+import com.hotdeal.alarm.worker.WorkerScheduler
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -86,6 +87,17 @@ fun SettingsScreen(viewModel: MainViewModel) {
             )
         }
 
+        // 폴<> 주기 설정
+        item {
+            PollingIntervalSection(
+                currentInterval = 2, // 기본 2분
+                onIntervalChange = { minutes ->
+                    viewModel.stopPolling()
+                    viewModel.startPolling(minutes)
+                }
+            )
+        }
+
         // 사이트 선택 섹션
         item {
             Text(
@@ -188,6 +200,80 @@ fun SettingsScreen(viewModel: MainViewModel) {
     }
 }
 
+@Composable
+fun PollingIntervalSection(
+    currentInterval: Int,
+    onIntervalChange: (Long) -> Unit
+) {
+    var selectedInterval by remember { mutableStateOf(currentInterval) }
+    
+    Card(
+        modifier = Modifier.fillMaxWidth(),
+        colors = CardDefaults.cardColors(
+            containerColor = MaterialTheme.colorScheme.secondaryContainer.copy(alpha = 0.3f)
+        )
+    ) {
+        Column(
+            modifier = Modifier.padding(16.dp),
+            verticalArrangement = Arrangement.spacedBy(12.dp)
+        ) {
+            Row(
+                verticalAlignment = Alignment.CenterVertically
+            ) {
+                Icon(
+                    imageVector = Icons.Default.Schedule,
+                    contentDescription = null,
+                    tint = MaterialTheme.colorScheme.secondary
+                )
+                Spacer(modifier = Modifier.width(12.dp))
+                Text(
+                    text = "폴<EFBFBD> 주기 설정",
+                    style = MaterialTheme.typography.titleMedium,
+                    fontWeight = FontWeight.Bold
+                )
+            }
+            
+            Text(
+                text = "핫딜을 확인하는 간격을 설정합니다.\n짧을수록 배터리와 데이터 소모가 증가합니다.",
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+            
+            // 간격 선택
+            Column {
+                listOf(1, 2, 5, 10, 15, 30).forEach { minutes ->
+                    Row(
+                        modifier = Modifier
+                            .fillMaxWidth()
+                            .padding(vertical = 4.dp),
+                        verticalAlignment = Alignment.CenterVertically
+                    ) {
+                        RadioButton(
+                            selected = selectedInterval == minutes,
+                            onClick = {
+                                selectedInterval = minutes
+                                onIntervalChange(minutes.toLong())
+                            }
+                        )
+                        Text(
+                            text = when (minutes) {
+                                1 -> "1분 (빠름 - 배터리 소모 큼)"
+                                2 -> "2분 (권장)"
+                                5 -> "5분 (보통)"
+                                10 -> "10분 (느림)"
+                                15 -> "15분 (매우 느림)"
+                                30 -> "30분 (절전)"
+                                else -> "${minutes}분"
+                            },
+                            style = MaterialTheme.typography.bodyMedium
+                        )
+                    }
+                }
+            }
+        }
+    }
+}
+
 @Composable
 fun PermissionStatusSection(
     permissionStatus: PermissionHelper.PermissionStatus,

app/src/main/java/com/hotdeal/alarm/worker/WorkerScheduler.kt

@@ -7,23 +7,41 @@ import java.util.concurrent.TimeUnit
 import javax.inject.Inject
 import javax.inject.Singleton
 
+/**
+ * Worker 스케줄러
+ * 
+ * 기본 폴<> 주기: 2분
+ * 배터리/데이터 절약을 위해 최소 2분 권장
+ */
 @Singleton
 class WorkerScheduler @Inject constructor(
     @ApplicationContext private val context: Context
 ) {
     companion object {
-        private const val DEFAULT_INTERVAL_MINUTES = 15L
+        const val DEFAULT_INTERVAL_MINUTES = 2L
+        const val MIN_INTERVAL_MINUTES = 1L
+        const val MAX_INTERVAL_MINUTES = 60L
     }
     
+    /**
+     * 주기적 폴<> 예약
+     * @param intervalMinutes 폴<> 간격 (분) - 기본 2분
+     */
     fun schedulePeriodicPolling(intervalMinutes: Long = DEFAULT_INTERVAL_MINUTES) {
+        // 최소/최대 값 제한
+        val safeInterval = intervalMinutes.coerceIn(MIN_INTERVAL_MINUTES, MAX_INTERVAL_MINUTES)
+        
         val constraints = Constraints.Builder()
             .setRequiredNetworkType(NetworkType.CONNECTED)
-            .setRequiresBatteryNotLow(true)
+            .setRequiresBatteryNotLow(true)  // 배터리 부족 시 실행 안 함
             .build()
         
+        // 유연한 실행 시간 (±25%)
+        val flexTime = (safeInterval * 0.25).toLong().coerceAtLeast(1)
+        
         val workRequest = PeriodicWorkRequestBuilder<HotDealPollingWorker>(
-            intervalMinutes, TimeUnit.MINUTES,
+            safeInterval, TimeUnit.MINUTES,
-            intervalMinutes / 3, TimeUnit.MINUTES
+            flexTime, TimeUnit.MINUTES
         )
             .setConstraints(constraints)
             .setBackoffCriteria(
@@ -41,6 +59,9 @@ class WorkerScheduler @Inject constructor(
         )
     }
     
+    /**
+     * 한 번만 실행
+     */
     fun executeOnce() {
         val constraints = Constraints.Builder()
             .setRequiredNetworkType(NetworkType.CONNECTED)
@@ -54,10 +75,16 @@ class WorkerScheduler @Inject constructor(
         WorkManager.getInstance(context).enqueue(workRequest)
     }
     
+    /**
+     * 폴<> 취소
+     */
     fun cancelPolling() {
         WorkManager.getInstance(context).cancelUniqueWork(HotDealPollingWorker.WORK_NAME)
     }
     
+    /**
+     * 폴<> 활성화 여부 확인
+     */
     fun isPollingActive(): Boolean {
         val workInfos = WorkManager.getInstance(context)
             .getWorkInfosForUniqueWork(HotDealPollingWorker.WORK_NAME)