add visual skip overlay for skipped opponents

- Create a red "X" overlay that animates onto the portrait of a skipped opponent
- Implement `showSkipOverlay` to render the effect using Phaser DOM objects
- Trigger the overlay when a player is skipped to provide clearer visual feedback

public/src/games/uno/UnoGame.js

@@ -1088,6 +1088,7 @@ export default class UnoGame extends Phaser.Scene {
       const e = after.log[i];
       if (e.kind === 'skip') {
         this.opponentPortraits[e.seat]?.playEmotion('upset');
+        this.showSkipOverlay(e.seat);
         this.showBanner(`${this.opponentName(e.seat)} is skipped!`);
         this.time.delayedCall(900, () => this.hideBanner());
       } else if (e.kind === 'reverse') {
@@ -1271,6 +1272,36 @@ export default class UnoGame extends Phaser.Scene {
     });
   }
 
+  showSkipOverlay(skippedSeat) {
+    const slot = this.slotForSeat[skippedSeat];
+    const layout = slotLayout(slot, this.gs.players.length);
+    const { x: px, y: py, r: pr } = layout.portrait;
+    const r = pr + 8;
+    const size = r * 2;
+    const strokeW = Math.round(r * 0.09);
+    const slashW = Math.round(r * 0.13);
+
+    // Build as a DOM element so it renders above the portrait video layer.
+    const el = document.createElement('div');
+    el.style.cssText = `width:${size}px;height:${size}px;border-radius:50%;background:transparent;border:${strokeW}px solid rgba(204,0,0,0.95);box-sizing:border-box;position:relative;overflow:hidden;`;
+    const slash = document.createElement('div');
+    slash.style.cssText = `position:absolute;width:${slashW}px;height:${Math.round(size * 1.1)}px;background:rgba(204,0,0,0.95);border-radius:${Math.round(slashW / 2)}px;top:50%;left:50%;transform:translate(-50%,-50%) rotate(-45deg);`;
+    el.appendChild(slash);
+
+    const domObj = this.add.dom(DISCARD_POS.x, DISCARD_POS.y, el);
+    domObj.setDepth(D.banner);
+    domObj.setScale(0.2);
+    this.transientObjs.push(domObj);
+
+    this.tweens.add({
+      targets: domObj,
+      x: px, y: py,
+      scaleX: 1, scaleY: 1,
+      duration: 1500,
+      ease: 'Back.easeOut',
+    });
+  }
+
   // ── Color picker modal ────────────────────────────────────────────────────
 
   openColorPicker(onPick) {