fix(widget): respect size for RawText and Spacer Widgets

src/render.zig

@@ -43,9 +43,9 @@ pub fn Buffered(comptime fullscreen: bool) type {
 
 pub fn Plain(comptime _: bool) type {
     return struct {
-        pub fn clear(this: @This(), anchor: Position, size: Size) !void {
+        pub fn clear(this: @This(), size: Size) !void {
             _ = this;
-            _ = size;
+            const anchor = size.anchor;
             // NOTE: clear entire screen for the first content (derived from the anchor being at the very left-top)
             if (anchor.col == 1 and anchor.row == 1) {
                 try terminal.clearScreen();