core: write scrollback file works again

src/Surface.zig

@@ -3230,12 +3230,15 @@ pub fn performBindingAction(self: *Surface, action: input.Binding.Action) !bool
                 // We only dump history if we have history. We still keep
                 // the file and write the empty file to the pty so that this
                 // command always works on the primary screen.
-                // TODO(paged-terminal): unwrap
+                const pages = &self.io.terminal.screen.pages;
+                if (pages.getBottomRight(.history)) |br| {
+                    const tl = pages.getTopLeft(.history);
                     try self.io.terminal.screen.dumpString(
                         file.writer(),
-                    .{ .history = .{} },
+                        .{ .tl = tl, .br = br, .unwrap = true },
                     );
                 }
+            }
 
             // Get the final path
             var path_buf: [std.fs.MAX_PATH_BYTES]u8 = undefined;