Fix What's New dialog layout and improve dev styling/debugging.

Portal the updates dialog to document.body with stable data attributes,
fix max-width (invalid S800 token), bundle update images for Capacitor,
and add readable vanilla-extract class names plus portalContainer tap fixes.

src/index.css

@@ -147,6 +147,27 @@ body.stationery-dark-theme {
   background-color: #262626;
 }
 
+/*
+ * Folds Overlay / PopOut portals mount here. The container must not steal taps;
+ * only its children should. Empty portal shells (e.g. closed overlays) must not
+ * block dialogs portaled elsewhere.
+ */
+#portalContainer {
+  position: fixed;
+  inset: 0;
+  z-index: 9998;
+  pointer-events: none;
+  overflow: hidden;
+}
+
+#portalContainer > * {
+  pointer-events: auto;
+}
+
+#portalContainer > *:empty {
+  pointer-events: none !important;
+}
+
 .twilight-theme #root {
   background: linear-gradient(180deg, rgba(28, 26, 46, 0.5) 0%, rgba(36, 34, 61, 0.3) 100%);
 }