fix: other demos

ts/index.html

@@ -154,12 +154,15 @@
         label: "Text (centered)",
         make() {
           return new MonoDisplayFile({
-            elements_always: [{
+            elements_always: {
+              flags: { drawFront: true, clearBuffer: true },
+              elements: [{
                 type: ElementType.ClippedText,
                 text: "Hello, World!",
                 xOffset: 0, yOffset: 32,
                 width: W, height: 16,
               }],
+            },
           }).toBuffer();
         },
       },
@@ -167,14 +170,17 @@
         label: "Scrolltext (left)",
         make() {
           return new MonoDisplayFile({
-            elements_always: [{
+            elements_always: {
+              flags: { drawFront: true, clearBuffer: true },
+              elements: [{
                 type: ElementType.HScrollText,
                 text: "MONO DISPLAY — scrolling ticker — 🚀 ",
                 xOffset: 0, yOffset: 32,
                 width: W, height: 16,
-              scrollSpeed: 50, // (50+1)/16 ≈ 3.2 px/tick at 25fps ≈ 80px/s
+                scrollSpeed: 50,
                 flags: { endless: true, invertDirection: false },
               }],
+            },
           }).toBuffer();
         },
       },