chore: upgrade Android examples to LeapSDK 0.9.7 with new model downloader

[iamstuffed]

Upgrade Android Examples to LeapSDK 0.9.7

This PR upgrades all Android examples to LeapSDK 0.9.7 and adopts the Android-specific LeapModelDownloader API for enhanced download management with platform-native features.

📦 Updated Examples

All 5 Android examples upgraded:

• ✅ SloganApp - Slogan generation demo
• ✅ LeapChat - Full-featured chat with tool calling
• ✅ RecipeGenerator - Constrained JSON output demo
• ✅ ShareAI - Web summary generator
• ✅ VLMExample - Vision language model demo

🆕 New Features

1. LeapModelDownloader - Android-Specific API

Migrated from KMP LeapDownloader to Android-specific LeapModelDownloader:

• LeapDownloader is the Kotlin Multiplatform (KMP) API - works on all platforms
• LeapModelDownloader is Android-specific and provides a superset of functionality
• Uses LeapDownloader internally while adding Android-native features:
  • 🔔 System notifications
  • 📊 WorkManager-based downloads
  • 📱 Android lifecycle awareness
  • ⚙️ Platform-optimized download management

Before (KMP API):

val downloader = LeapDownloader(
    config = LeapDownloaderConfig(saveDir = "$filesDir/leap_models")
)
modelRunner = downloader.loadModel(
    modelName = "Model-Name",
    quantizationSlug = "Q8_0"
)

After (Android API):

val downloader = LeapModelDownloader(
    context,
    notificationConfig = LeapModelDownloaderNotificationConfig.build {
        notificationTitleDownloading = "Downloading Model"
        notificationTitleDownloaded = "Model Ready!"
    }
)
modelRunner = downloader.loadModel(
    modelName = "Model-Name",
    quantizationType = "Q8_0"
)

2. Download Progress Tracking 📊

Real-time download progress with Flow-based status updates:

val currentStatus = downloader.queryStatus(modelName, quantType)

if (currentStatus is ModelDownloadStatus.NotOnLocal) {
    val progressFlow = downloader.observeDownloadProgress(modelName, quantType)
    downloader.requestDownloadModel(modelName, quantType)

    progressFlow
        .onEach { progress ->
            // Display: "Downloading: 45% (120 MB / 500 MB)"
        }
        .takeWhile { progress ->
            progress != null || downloader.queryStatus(modelName, quantType) is DownloadInProgress
        }
        .collect()
}

3. Android System Notifications 🔔

Platform-native notifications during model downloads with custom per-app titles:

• SloganApp: "Downloading Slogan Generator Model"
• LeapChat: "Downloading Chat Model"
• RecipeGenerator: "Downloading Recipe Generator Model"
• ShareAI: "Downloading ShareAI Model"
• VLMExample: "Downloading VLM Model"

4. Singleton Pattern 🔒

Prevents concurrent download issues by reusing downloader instance:

private var downloader: LeapModelDownloader? = null

// Reuse instance across calls
if (downloader == null) {
    downloader = LeapModelDownloader(context, notificationConfig)
}

5. Cleaner Flow Control 🎨

Separated concerns for better readability:

progressFlow
    .onEach { progress -> /* display logic */ }
    .takeWhile { progress -> /* control logic */ }
    .collect()

🔄 API Changes

Updated Dependencies

// Added to all examples
implementation(libs.leap.sdk)              // Updated to 0.9.7
implementation(libs.leap.model.downloader) // New Android-specific module

Parameter Renames

More semantic and consistent:

• quantizationSlug → quantizationType

Permissions Added

<!-- For Android 13+ notification support -->
<uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>

📊 Statistics

• Files changed: 31
• Lines added: 578
• Lines removed: 183
• Net change: +395 lines
• Commits: 3 (squashed from original development)

✨ Benefits

1. Better UX: Users see real-time download progress and system notifications
2. Platform-Native: Leverages Android's WorkManager and notification system
3. Robustness: Singleton pattern prevents concurrent download conflicts
4. Maintainability: Cleaner code with separated concerns
5. Feature-Rich: Access to Android-specific features while maintaining KMP compatibility
6. Consistency: All examples follow the same pattern

💡 Why LeapModelDownloader?

While LeapDownloader (KMP) works perfectly on Android, LeapModelDownloader provides:

• ✅ Android notifications - Keep users informed via notification tray
• ✅ WorkManager integration - Reliable downloads even if app is backgrounded
• ✅ Better progress tracking - Platform-optimized download monitoring
• ✅ Lifecycle awareness - Proper handling of Android app lifecycle
• ✅ All KMP features - Uses LeapDownloader internally as the foundation

Both APIs remain available - use LeapDownloader for KMP projects, LeapModelDownloader for Android-specific apps that want enhanced features.

📝 Documentation

• Added LeapKoogAgent to main README (was missing from examples list)
• Fixed LeapChat README to reflect Kotlin Serialization usage (not Gson)
• Enhanced RecipeGenerator README with download details

🔄 Dependency Updates

All Android examples updated to latest stable versions:

• Kotlin: 2.3.0 → 2.3.10
• Compose BOM: 2025.12.01 → 2026.01.01
• activity-compose: 1.12.2 → 1.12.3
• kotlinx-serialization-json: 1.8.0 → 1.10.0
• jsoup: 1.16.1 → 1.22.1 (ShareAI)
• kaml: 0.85.0 → 0.104.0 (VLMExample)

Kept AGP at 8.13.2 (skipped 9.0.0 major version to avoid breaking changes).

🧪 Testing

All examples tested with:

• ✅ First-time model downloads
• ✅ Progress tracking and notifications
• ✅ Model loading after download
• ✅ Concurrent download prevention
• ✅ Clean flow control logic
• ✅ Background download handling

🔗 Related

• Upgrades from LeapSDK 0.9.6 to 0.9.7
• Uses new leap-model-downloader artifact from Maven Central
• Compatible with Android API 31+
• Maintains backward compatibility with KMP LeapDownloader for multiplatform projects