feat: add automatic sync on MainScreen resume

- Add lifecycle observer to detect when MainScreen is resumed
- Automatically trigger data sync when app returns to foreground
- Import lifecycle dependencies (LocalLifecycleOwner, Lifecycle, LifecycleEventObserver)
- Use DisposableEffect for proper lifecycle observer cleanup
- Improve user experience with fresh data when returning to app
- Handle app backgrounding, screen lock, and navigation scenarios

Author: dpconde

app/src/main/java/com/dpconde/sofiatracker/presentation/main/MainScreen.kt

@@ -10,6 +10,9 @@ import androidx.compose.material.icons.filled.Add
 import androidx.compose.material3.*
 import androidx.compose.runtime.*
 import androidx.compose.ui.Alignment
+import androidx.compose.ui.platform.LocalLifecycleOwner
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.LifecycleEventObserver
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.graphics.Color
@@ -51,6 +54,20 @@ fun MainScreen(
     viewModel: MainScreenViewModel = hiltViewModel()
 ) {
     val uiState by viewModel.uiState.collectAsState()
+    val lifecycleOwner = LocalLifecycleOwner.current
+    
+    // Trigger sync when screen is resumed
+    DisposableEffect(lifecycleOwner) {
+        val observer = LifecycleEventObserver { _, event ->
+            if (event == Lifecycle.Event.ON_RESUME) {
+                viewModel.triggerSync()
+            }
+        }
+        lifecycleOwner.lifecycle.addObserver(observer)
+        onDispose {
+            lifecycleOwner.lifecycle.removeObserver(observer)
+        }
+    }
 
     Scaffold(
         topBar = {