Fix code review branch selector overlay

Anchor the diff selector menu to the saved trigger position so the overlay remains correctly positioned and interactive after pane relayouts, including maximized code review view.

Co-Authored-By: Oz <oz-agent@warp.dev>

Author: 2 people

app/src/code_review/diff_selector.rs

@@ -5,8 +5,8 @@ use warp_core::ui::theme::Fill;
 use warpui::{
     elements::{
         ChildAnchor, ChildView, ConstrainedBox, Container, CornerRadius, CrossAxisAlignment,
-        Element, Flex, MouseStateHandle, OffsetPositioning, ParentAnchor, ParentElement,
-        ParentOffsetBounds, Radius, Stack, Text,
+        Element, Flex, MouseStateHandle, OffsetPositioning, ParentElement, PositionedElementAnchor,
+        PositionedElementOffsetBounds, Radius, SavePosition, Stack, Text,
     },
     fonts::{Properties, Weight},
     id,
@@ -58,6 +58,7 @@ pub struct DiffSelector {
     menu: ViewHandle<CodeReviewDiffMenu>,
     menu_open: bool,
     trigger_mouse_state: MouseStateHandle,
+    trigger_position_id: String,
     /// Cached label for the trigger button; mirrors the selected `DiffTarget`.
     trigger_label: String,
 }
@@ -97,6 +98,7 @@ impl DiffSelector {
         });
 
         Self {
+            trigger_position_id: format!("code_review_diff_selector_trigger_{}", menu.id()),
             menu,
             menu_open: false,
             trigger_mouse_state: MouseStateHandle::default(),
@@ -245,16 +247,18 @@ impl View for DiffSelector {
                 ctx.dispatch_typed_action(DiffSelectorAction::Toggle);
             })
             .finish();
+        let trigger = SavePosition::new(trigger, &self.trigger_position_id).finish();
 
         let mut stack = Stack::new().with_child(trigger);
 
         if self.menu_open {
             stack.add_positioned_overlay_child(
                 ChildView::new(&self.menu).finish(),
-                OffsetPositioning::offset_from_parent(
+                OffsetPositioning::offset_from_save_position_element(
+                    self.trigger_position_id.as_str(),
                     vec2f(0., MENU_OFFSET_Y),
-                    ParentOffsetBounds::WindowByPosition,
-                    ParentAnchor::BottomLeft,
+                    PositionedElementOffsetBounds::WindowByPosition,
+                    PositionedElementAnchor::BottomLeft,
                     ChildAnchor::TopLeft,
                 ),
             );