fix: resolve TypeScript build errors in FloatingPromptInput

- Add explicit type annotation to drag-drop event handler
- Remove unused IME composition handler functions
- Update bun.lock with new optional dependencies

These fixes allow the build to complete successfully after
merging PR winfunc#365.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: Sallvainian

bun.lock

@@ -411,7 +411,7 @@ const FloatingPromptInputInner = (
         }
 
         const webview = getCurrentWebviewWindow();
-        unlistenDragDropRef.current = await webview.onDragDropEvent((event) => {
+        unlistenDragDropRef.current = await webview.onDragDropEvent((event: any) => {
           if (event.payload.type === "enter" || event.payload.type === "over") {
             setDragActive(true);
           } else if (event.payload.type === "leave") {
@@ -722,16 +722,6 @@ const FloatingPromptInputInner = (
     }, 0);
   };
 
-  const handleCompositionStart = () => {
-    isIMEComposingRef.current = true;
-  };
-
-  const handleCompositionEnd = () => {
-    setTimeout(() => {
-      isIMEComposingRef.current = false;
-    }, 0);
-  };
-
   const isIMEInteraction = (event?: React.KeyboardEvent) => {
     if (isIMEComposingRef.current) {
       return true;