@ context menu fixes. (#9237)

## Description
<!-- Please remember to add your design buddy onto the PR for review, if
it contains any UI changes! -->

WISOTT! Fixes:
- positioning of the menu in the new cloud mode input
- some sharp corners poking through rounded ones for the selected item

<img width="588" height="312" alt="Screenshot 2026-04-27 at 9 01 19 PM"
src="https://github.com/user-attachments/assets/03cd565a-e869-4a3a-9ae3-98dd3d86c068"
/>


## Testing
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See image!

## Agent Mode
- [x] Warp Agent Mode - This PR was created via Warp's AI Agent Mode

app/src/terminal/input/agent.rs

@@ -333,7 +333,7 @@ impl Input {
         let menu_positioning = self.menu_positioning(app);
         let model = self.model.lock();
 
-        let mut stack = Stack::new().with_constrain_absolute_children();
+        let mut stack = Stack::new();
 
         // Apply the V2 gutter symmetrically (left + right) so the floating
         // input keeps equal breathing room on both sides as the pane shrinks.