Make every tvOS switcher a menu and retire the full-screen picker

The header button and the settings row both raised a fullScreenCover to
pick a context; a Menu offers the same rows in place for one click,
matching the pickers elsewhere in Settings. With every presentation now
a menu, the picker view and the rows' inMenu flag had nothing left to
serve. The subscriptions header also cedes its width to the account
name: the view-options button keeps only its icon, since two full
titles wrapped into tall two-line lozenges in the tvOS sidebar.

Yattee/Views/Subscriptions/SubscriptionsView.swift

@@ -906,12 +906,18 @@ struct SubscriptionsView: View {
     #if os(tvOS)
     private var tvOSViewOptionsButton: some View {
         HStack(spacing: 16) {
+            // The sidebar is too narrow for both buttons' full titles, and
+            // tvOS wraps them into tall two-line lozenges before truncating.
+            // The account name is the label worth keeping whole, so this
+            // button keeps only its icon and the name gets the width.
             Button {
                 showViewOptions = true
             } label: {
                 Label(String(localized: "viewOptions.title"), systemImage: "slider.horizontal.3")
+                    .labelStyle(.iconOnly)
             }
             .buttonStyle(.bordered)
+            .accessibilityLabel(Text(String(localized: "viewOptions.title")))
 
             if DataContextSwitcherVisibility.showsPickers(in: appEnvironment) {
                 DataContextSwitcherButton()