fix: increase z-index of context menu to prevent UI obstruction

- Changed z-index from 1000 to 10001 in ChatTextArea.tsx
- Changed z-index from 1000 to 10001 in ContextMenu.tsx
- This ensures the @ mention dropdown appears above other UI elements
- Fixes #7759

Author: roomote

webview-ui/src/components/chat/ChatTextArea.tsx

@@ -954,7 +954,7 @@ export const ChatTextArea = forwardRef<HTMLTextAreaElement, ChatTextAreaProps>(
 									"bottom-full",
 									"left-0",
 									"right-0",
-									"z-[1000]",
+									"z-[10001]",
 									"mb-2",
 									"filter",
 									"drop-shadow-md",

webview-ui/src/components/chat/ContextMenu.tsx

@@ -268,7 +268,7 @@ const ContextMenu: React.FC<ContextMenuProps> = ({
 					border: "1px solid var(--vscode-editorGroup-border)",
 					borderRadius: "3px",
 					boxShadow: "0 4px 10px rgba(0, 0, 0, 0.25)",
-					zIndex: 1000,
+					zIndex: 10001,
 					display: "flex",
 					flexDirection: "column",
 					maxHeight: "300px",