Reset per-game reveal state on new game so reveal animates over cached content

Starting a new game reuses block ids (1,2,3...). The reveal clock's per-block
start times (activeRevealBlockStarts in the lab) and the renderer's animation/
revealed sets are keyed by block id and were never cleared on a client reset, so
a new game over already-cached content inherited the previous run's start times.
beginPageReveal then computed a huge elapsed and the shader treated the reveal as
already complete — showing everything at once instead of animating.

resetClientPlaybackAndDisplay (run on new game and restore) now emits
story:client-reset; the lab clears activeRevealBlockStarts/pending reveal state,
the texture renderer clears active animations and revealed-block ids, and the
timeline invalidates prepared segments. So each game starts with a clean reveal
clock.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

public/js/game-loop-module.js

@@ -657,8 +657,15 @@ class GameLoopModule extends BaseModule {
         if (inputHandler && typeof inputHandler.clearHistory === 'function') {
             inputHandler.clearHistory();
         }
+
+        // Signal a client reset so transient, block-id-keyed reveal/animation state is
+        // cleared. Without this, a new game that reuses block ids over already-cached
+        // content keeps the previous run's reveal start times and skips the animation.
+        document.dispatchEvent(new CustomEvent('story:client-reset', {
+            detail: { reason: 'client-reset' }
+        }));
     }
-    
+
 }
 
 // Create the singleton instance