fix(canvas): remove TS cast from inline script (Vite builds as JS)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

website/canvas.html

@@ -3067,7 +3067,7 @@
 
 			// Wire history revert
 			document.querySelector("rstack-history-panel")?.addEventListener("revert-requested", (e) => {
-				const { hash } = (e as CustomEvent).detail;
+				const hash = e.detail?.hash;
 				if (hash) sync.revertToHash(hash);
 			});