Fix MIST gallery scene controls, video positioning and audio overlap

frontend/src/player/screens.ts

@@ -1400,6 +1400,19 @@ export class ScreenManager {
     const sensitive = props.sensitive ? truthy(this.ev(props.sensitive)) && this.actionSensitive(action) : this.actionSensitive(action);
     const selected = props.selected ? truthy(this.ev(props.selected)) : this.actionSelected(action);
     let hover = false;
+    // Keep every state in the same grid cell. Replacing the idle image with an
+    // unloaded hover image collapses the hit area and causes enter/leave loops.
+    const pictures = new Map<any, HTMLElement>();
+    if (images) for (const file of Object.values(images)) {
+      if (!file || pictures.has(file)) continue;
+      const picture = this.displayable(file);
+      if (!picture) continue;
+      picture.classList.add("pg-simg");
+      picture.style.gridArea = "1 / 1";
+      picture.style.pointerEvents = "none";
+      pictures.set(file, picture);
+      el.append(picture);
+    }
     const paint = () => {
       const state = !sensitive ? (selected ? "selected_insensitive" : "insensitive")
         : selected ? (hover ? "selected_hover" : "selected_idle") : hover ? "hover" : "idle";
@@ -1409,10 +1422,7 @@ export class ScreenManager {
       }
       el.dataset.state = state;
       if (images) {
-        const file = images[state];
-        const picture = file ? this.displayable(file) : null;
-        el.replaceChildren(...(picture ? [picture] : []));
-        picture?.classList.add("pg-simg");
+        for (const [file, picture] of pictures) picture.style.opacity = file === images[state] ? "1" : "0";
       } else {
         this.look(el, props, state);
         if (label) this.textLook(label, { ...props, ...Object.fromEntries(Object.entries(textProps).map(([k, v]) => [k, v])) }, state);
@@ -1741,7 +1751,9 @@ export class ScreenManager {
 
   /** Run what a widget's `action` evaluated to. */
   run(action: any, screen: Instance | null) {
-    if (this.suspended) return;
+    // Absent hover actions must not rebuild the button under the pointer:
+    // its replacement would receive mouseenter again and replay hover_sound.
+    if (this.suspended || action === null || action === undefined || action === false) return;
     // actions act on the game, not on the screen's own variable scope
     const { py } = this.host;
     const savedFn = py.fn;