Move copy, paste and presets into the develop top bar

They sat in the develop column under a "SETTINGS" heading, which read as
application settings, and went away with the panel toggle and in the
mask and spot modes. The strip is where undo already is for the same
reason: these act on the whole edit, not on any one panel.

The paste button still names what it would apply. The TransferPanel
component is gone; the Transfer global and its Rust wiring are
unchanged.

ui/dr-ui/ui/adjust.slint

@@ -886,64 +886,6 @@ export global Transfer {
     callback open-presets();
 }
 
-// TRACES: FR-DEV-6
-// Copying this photograph's settings, and pasting settings onto it.
-//
-// Buttons rather than a keyboard shortcut *alone*, because this has to work on
-// a tablet where there is no modifier key to hold and no menu bar to hang the
-// action from. The desktop shortcuts exist as well, wired in Rust; they are an
-// accelerator for a control that is on screen either way, which is what keeps
-// the feature discoverable on both platforms.
-//
-// The paste button carries what would be pasted rather than the bare word.
-// "Paste" alone asks the user to remember what they copied and, crucially,
-// whether the crop is coming with it — a question the label answers by
-// naming the count the *current* scope would apply.
-export component TransferPanel inherits VerticalLayout {
-    padding: Theme.gap;
-    spacing: Theme.gap-sm;
-
-    HorizontalLayout {
-        PanelHeading { text: "SETTINGS"; }
-        Rectangle { horizontal-stretch: 1; }
-    }
-
-    HorizontalLayout {
-        spacing: Theme.gap-sm;
-
-        Button {
-            text: "Copy";
-            enabled: Develop.enabled;
-            horizontal-stretch: 1;
-            clicked => { Transfer.copy(); }
-        }
-
-        Button {
-            text: "Paste";
-            // Enabled on `armed` rather than on the summary being non-empty,
-            // so pasting a neutral copy — which clears this image — stays
-            // available. Still needs an image to paste *onto*.
-            enabled: Develop.enabled && Transfer.armed;
-            horizontal-stretch: 1;
-            clicked => { Transfer.paste(); }
-        }
-    }
-
-    // TRACES: FR-DEV-6
-    // The saved half. On its own row rather than a third of the one above,
-    // because copy and paste are a pair — one arms the other — and a button
-    // that does neither sitting between them would read as part of that pair.
-    Button {
-        text: "Presets…";
-        enabled: Develop.enabled;
-        clicked => { Transfer.open-presets(); }
-    }
-
-    if Transfer.armed: Caption {
-        text: Transfer.summary + (Transfer.framing-withheld ? " · crop not included" : "");
-    }
-}
-
 /// TRACES: FR-DEV-3
 /// The generated controls: what they show, what they are pointed at, and what
 /// pressing one means.