Adopt Jetpack Compose UI

[mehdikhalifeh]

Motivation

• Modernize the app UI to use Jetpack Compose and Material3 for a simpler, declarative UI implementation.
• Reduce reliance on legacy XML view hierarchies and AppCompat activity classes by migrating to Compose and ComponentActivity.
• Enable Compose build features in the module to allow future Compose development and previews.

Description

• Enabled Compose in app/build.gradle.kts with buildFeatures.compose = true, added Compose BOM and dependencies such as activity-compose and material3.
• Replaced XML-based MainActivity, SearchActivity, and FavoriteActivity implementations with Kotlin ComponentActivity classes that call setContent and provide composable screens (MainScreen, SimpleScreen, ActionButton).
• Updated app/src/main/res/values/styles.xml to use a Material3 theme (Theme.Material3.DayNight.NoActionBar) and adjusted color attributes for Compose compatibility.
• Updated AndroidManifest.xml to mark MainActivity as android:exported="true" and aligned manifest usage with the Kotlin DSL namespace approach.

Testing

• No automated tests were executed for this change.
• Manual verification was not reported in the automated rollout logs.

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Codex Task