MAUI: Preparation for WebView Integration

[sultanaalyami]

Description

Abstract platform-specific code for future MAUI WebView integration.

Tasks

• Abstract browser launch into IAppLauncher interface
• Abstract file system access for platform portability
• Document MAUI WebView integration points
• Ensure no Windows-only APIs in new premium code
• Create MAUI compatibility test matrix

Dependencies

Depends on: Dynamic Menu State Toggle

Context

Prepares the codebase for the transition to MAUI as noted in the project roadmap.

Migrated from: WasmMvcRuntime #47