The action buttons inside ItemsControl item templates (Télécharger /
Supprimer / Joindre on MyFiles; download/detach on the attachment
lists of BillingQueryDetailsPage and EstimateEditionPage) were bound
with $parent[vm:XxxViewModel].Cmd, which searches for an ancestor
CONTROL of type XxxViewModel — a viewmodel, not a control — so the
binding resolved to null and the Button stayed disabled (grayed) and
inert on click. Switch to the working CirclesPage/EstimateListPage
syntax: $parent[ContentPage].((vm:XxxViewModel)DataContext).Cmd.
Adds MyFilesPageHeadlessTests: mounts MyFilesPage via NavigationPage
+ Window.Show() and asserts each row button's Command is bound,
armed (CanExecute), and fires the API call on click. 136/136 pass.
Co-Authored-By: Claude Code <noreply@anthropic.com>
