feat(04-01): Android config, NotificationService, DAO queries, timezone init, ARB strings

- Add flutter_local_notifications ^21.0.0, timezone ^0.11.0, flutter_timezone ^1.0.8 to pubspec.yaml
- Set compileSdk=35, enable core library desugaring in build.gradle.kts
- Add POST_NOTIFICATIONS, RECEIVE_BOOT_COMPLETED permissions and boot receivers to AndroidManifest.xml
- Create NotificationService singleton with initialize, requestPermission, scheduleDailyNotification, cancelAll
- Add getOverdueAndTodayTaskCount and getOverdueTaskCount one-shot queries to DailyPlanDao
- Initialize timezone and NotificationService in main.dart before runApp
- Add 7 notification-related ARB strings to app_de.arb
- All 72 existing tests pass

android/app/build.gradle.kts

@@ -7,10 +7,11 @@ plugins {
 
 android {
     namespace = "com.jlmak.household_keeper"
-    compileSdk = flutter.compileSdkVersion
+    compileSdk = 35
     ndkVersion = flutter.ndkVersion
 
     compileOptions {
+        isCoreLibraryDesugaringEnabled = true
         sourceCompatibility = JavaVersion.VERSION_17
         targetCompatibility = JavaVersion.VERSION_17
     }
@@ -42,3 +43,7 @@ android {
 flutter {
     source = "../.."
 }
+
+dependencies {
+    coreLibraryDesugaring("com.android.tools:desugar_jdk_libs:2.1.4")
+}