Feat: Add in-app review prompt

This commit integrates the Google Play In-App Review API, prompting users to rate the app after winning a game.

- **`ReviewPromptManager`** and **`ReviewPromptRepository`** are introduced to handle the review flow logic, timing, and state persistence using DataStore.
- The prompt is triggered from the `GameViewModel` after a player wins a game, subject to configurable timing and cooldown periods.
- Includes a fallback to redirect to the Play Store if the in-app review flow isn't available.
- New dependencies for Google Play Review (`com.google.android.play:review`) are added.
- A detailed documentation file, `REVIEW_PROMPT_INTEGRATION.md`, is included.

Fix: Refresh UI config periodically and update icon URL regex

This commit introduces a periodic refresh for the `UIConfig` and updates the regex for user avatar URLs.

- The `UIConfig` will now be considered stale and refreshed after one hour to ensure data, such as the user JWT, is up-to-date.
- A timestamp is now stored in `PersistenceManager` whenever the `UIConfig` is saved.
- The `UserSessionRepository` uses this timestamp to determine if a refresh is needed.
- The regex in `Globals.kt` for processing user avatar icons has been updated from `rackcdn.com` to the new `user-uploads.online-go.com` domain.

Fix: Remove splash screen

This commit removes the splash screen logic entirely.

- The `core-splashscreen` dependency is removed.
- All related code in `MainActivity`, `MyGamesUI`, and `MainActivityViewModel` has been deleted, including the `installSplashScreen` call, `setKeepOnScreenCondition`, and the logic that waited for initial data to load before hiding the splash screen.
- Splash screen-related styles have also been removed from `styles.xml`.

Fix: Update KSP to `2.2.21-RC-2.0.4`

This commit updates the KSP (Kotlin Symbol Processing) version in `gradle/libs.versions.toml`.

Chore: Update splashscreen dependency

Updates the `androidxCoreSplashscreen` library from `1.0.1` to `1.2.0-rc01`.

Refactor: Simplify Splash Screen Logic

This commit simplifies the splash screen dismissal condition in `MainActivity`.

Refactor: Simplify screen readiness logic in MyGamesUI

This commit removes the `hasReceivedHistoricGames` check from the `screenReady` condition in `MyGamesUI`. It also removes an unnecessary `withContext(Dispatchers.Default)` block from the `LaunchedEffect` that calls `onScreenReady`.

Feat: Re-enable splash screen logic

This commit re-enables the splash screen logic in `MainActivity` and `MyGamesUI`.

- The `setKeepOnScreenCondition` in `MainActivity` is now active, keeping the splash screen visible until the app has window focus and the initial data is loaded.
- The corresponding logic in `MyGamesUI` that determines when the screen is ready for display (i.e., when all initial game data is received or the user is logged out) has also been uncommented.
- A 2-second timeout is included to dismiss the splash screen even if data loading is delayed.

Refactor: Re-enable Splash Screen

Refactor: Enable network stack pre-warming

This commit re-enables the pre-warming of the network stack in `OnlineGoApplication.kt`.