agent: Fix @mention menu placement (#51817)

crates/agent_ui/src/message_editor.rs

@@ -16,10 +16,9 @@ use agent_client_protocol as acp;
 use anyhow::{Result, anyhow};
 use collections::HashSet;
 use editor::{
-    Addon, AnchorRangeExt, ContextMenuOptions, ContextMenuPlacement, Editor, EditorElement,
-    EditorEvent, EditorMode, EditorStyle, Inlay, MultiBuffer, MultiBufferOffset,
-    MultiBufferSnapshot, ToOffset, actions::Paste, code_context_menus::CodeContextMenu,
-    scroll::Autoscroll,
+    Addon, AnchorRangeExt, ContextMenuOptions, Editor, EditorElement, EditorEvent, EditorMode,
+    EditorStyle, Inlay, MultiBuffer, MultiBufferOffset, MultiBufferSnapshot, ToOffset,
+    actions::Paste, code_context_menus::CodeContextMenu, scroll::Autoscroll,
 };
 use futures::{FutureExt as _, future::join_all};
 use gpui::{
@@ -141,7 +140,7 @@ impl MessageEditor {
             editor.set_context_menu_options(ContextMenuOptions {
                 min_entries_visible: 12,
                 max_entries_visible: 12,
-                placement: Some(ContextMenuPlacement::Above),
+                placement: None,
             });
             editor.register_addon(MessageEditorAddon::new());