- Added Cairo-based window snapshot conversion (with unpremultiplication) for drag icons and updated drag rendering to use the new helper instead of drawable capture.

- Updated GtkXText to track the draw window and use a pixmap-to-surface helper for Cairo contexts, avoiding drawable references in the struct and rendering flow.
- Added a Cairo helper for capturing window-backed surfaces and used it when blitting during scrolling, fixing the build break from the removed drawable helper.

src/fe-gtk/xtext.h

@@ -131,7 +131,7 @@ struct _GtkXText
 
 	GtkAdjustment *adj;
 	GdkPixmap *pixmap;				/* 0 = use palette[19] */
-	GdkDrawable *draw_buf;			/* points to ->window */
+	GdkWindow *draw_window;			/* points to ->window */
 	cairo_surface_t *draw_surface;	/* temporary surface for offscreen draws */
 	GdkCursor *hand_cursor;
 	GdkCursor *resize_cursor;