WIP: use viewport to allow sizes of scroll to extend further than renderable screen

src/app.zig

@@ -7,7 +7,7 @@ const mergeTaggedUnions = event.mergeTaggedUnions;
 const isTaggedUnion = event.isTaggedUnion;
 
 const Key = @import("key.zig");
-const Size = @import("size.zig");
+const Size = @import("size.zig").Size;
 const Queue = @import("queue.zig").Queue;
 
 const log = std.log.scoped(.app);