Enhance sample app with all API demonstrations

## Description
Expand the sample application to demonstrate all available UXCam-KMP APIs.

## Current State
Basic initialization and simple event logging

## Target State
- Demonstrate all UXCam APIs
- Show configuration options
- Include privacy/occlusion examples
- Add session management controls
- Show user identification flow

## Platforms
- Android (Jetpack Compose)
- iOS (SwiftUI)