Refactor: Remove background task management and related hooks

- Deleted `useBackgroundTasks.ts` hook and its associated logic for managing background tasks.
- Removed `backgroundTaskManager.ts` service and all related task definitions and registrations.
- Cleaned up `Podfile.lock` and `package.json` to remove unused dependencies related to background tasks.
- Updated iOS project files to eliminate references to removed background task components.
- Added new background fetch identifier in `Info.plist` for future use.

android/build.gradle

@@ -1,37 +0,0 @@
-// Top-level build file where you can add configuration options common to all sub-projects/modules.
-
-buildscript {
-  repositories {
-    google()
-    mavenCentral()
-  }
-  dependencies {
-    classpath('com.android.tools.build:gradle')
-    classpath('com.facebook.react:react-native-gradle-plugin')
-    classpath('org.jetbrains.kotlin:kotlin-gradle-plugin')
-  }
-}
-
-def reactNativeAndroidDir = new File(
-  providers.exec {
-    workingDir(rootDir)
-    commandLine("node", "--print", "require.resolve('react-native/package.json')")
-  }.standardOutput.asText.get().trim(),
-  "../android"
-)
-
-allprojects {
-  repositories {
-    maven {
-      // All of React Native (JS, Obj-C sources, Android binaries) is installed from npm
-      url(reactNativeAndroidDir)
-    }
-
-    google()
-    mavenCentral()
-    maven { url 'https://www.jitpack.io' }
-  }
-}
-
-apply plugin: "expo-root-project"
-apply plugin: "com.facebook.react.rootproject"