.NET MAUI File Handling

Critical: Always Use OpenReadAsync(), Not FullPath

Some platforms (especially Android) return content URIs, not file system paths. Reading FullPath directly will throw or return empty data.

// ❌ Breaks on Android — FullPath may be a content:// URI
var result = await FilePicker.Default.PickAsync();
var bytes = File.ReadAllBytes(result.FullPath);

// ✅ Works on all platforms
var result = await FilePicker.Default.PickAsync();
if (result is not null)
{
    using var stream = await result.OpenReadAsync();
    // process stream
}