Viewer polish, cursor fix, Grok rename + W/S fix, Composer G teleport

Site:
- Cursor follower fades out over iframes (it froze on top of running
  artifacts since iframes swallow pointer events) and when the pointer
  leaves the window
- HTML viewer: full-bleed width on xl screens (up to 90rem), height
  capped to 100dvh-10rem so the frame plus its action row always fits
  the viewport (big iframes ate wheel events and trapped page scroll),
  fullscreen button (overlay + footer action), and Run now auto-aligns
  the frame below the fixed header

Artifacts:
- grok-build: W/S were inverted against the forward vector (W walked
  backward); model label renamed to Grok Build
- composer-2-5: added G-key cycle teleport to its three generated
  landmarks (elven tower, dragon temple, sky ruins) with a start-screen
  hint - they were previously only reachable on foot; ground landmarks
  arrive 10 blocks out facing the structure, sky ruins land on the deck

Run notes updated accordingly.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

outputs/composer-2-5/mythos-craft.html

@@ -85,7 +85,8 @@
     鼠标环视 · 左键破坏 · 右键放置<br>
     1-9 切换方块 · 滚轮切换物品<br>
     探索柏林噪声生成的无限大地<br>
-    发现精灵塔、龙神殿、天空遗迹等神话建筑
+    发现精灵塔、龙神殿、天空遗迹等神话建筑<br>
+    G 依次瞬移到三处神话景点
   </p>
   <div class="start">点击开始探索</div>
 </div>
@@ -1313,8 +1314,27 @@ document.addEventListener('mousemove', (e) => {
   player.pitch = Math.max(-Math.PI / 2 + 0.01, Math.min(Math.PI / 2 - 0.01, player.pitch));
 });
 
+// added: G cycles teleports through the generated landmarks (the structures
+// exist in world.structures but were otherwise only reachable on foot)
+let landmarkIndex = 0;
+
 document.addEventListener('keydown', (e) => {
   player.keys[e.code] = true;
+  if (e.code === 'KeyG') {
+    const struct = world.structures[landmarkIndex++ % world.structures.length];
+    const isSky = struct.name === '天空遗迹';
+    // sky ruins: land on the floating deck; ground landmarks: arrive a few
+    // blocks out, facing the structure
+    const tx = struct.x + (isSky ? 6.5 : 10.5);
+    const tz = struct.z + (isSky ? 0.5 : 10.5);
+    const groundY = isSky
+      ? world.getHeight(Math.round(struct.x), Math.round(struct.z))
+      : world.getHeight(Math.round(tx), Math.round(tz));
+    player.position.set(tx, groundY + (isSky ? 23 : 3), tz);
+    player.velocity.set(0, 0, 0);
+    player.yaw = Math.atan2(tx - struct.x, tz - struct.z);
+    player.pitch = 0;
+  }
   if (e.code.startsWith('Digit') && e.code !== 'Digit0') {
     const n = parseInt(e.code.replace('Digit', '')) - 1;
     if (n >= 0 && n < HOTBAR_BLOCKS.length) selectSlot(n);

outputs/grok-build/mythos-craft.html

@@ -1177,8 +1177,8 @@
         );
 
         let moveX = 0, moveZ = 0;
-        if (this.keys['KeyW']) moveZ -= 1;
-        if (this.keys['KeyS']) moveZ += 1;
+        if (this.keys['KeyW']) moveZ += 1; // fix: W/S were inverted — `forward` already points where the camera looks, so W must add +forward (it walked backward before)
+        if (this.keys['KeyS']) moveZ -= 1;
         if (this.keys['KeyA']) moveX -= 1;
         if (this.keys['KeyD']) moveX += 1;