Add MindSpace visual page editor and Plaza local Tunnel deployment.

In-preview HTML editing with undo/redo sync replaces Agent patch auto-save; Plaza runs on local Mac via Cloudflare Tunnel with embed height and CSP fixes.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/hooks/usePageDraftHistory.ts

@@ -67,28 +67,28 @@ export function usePageDraftHistory(initial: PageDraftSnapshot) {
     [flushDebounced, snapshot],
   );
 
-  const undo = useCallback(() => {
+  const undo = useCallback((): PageDraftSnapshot | null => {
     flushDebounced();
     const previous = pastRef.current[pastRef.current.length - 1];
-    if (!previous) return false;
+    if (!previous) return null;
     pastRef.current = pastRef.current.slice(0, -1);
     futureRef.current = [snapshot, ...futureRef.current];
     stableRef.current = previous;
     setSnapshot(previous);
     bump();
-    return true;
+    return previous;
   }, [flushDebounced, snapshot]);
 
-  const redo = useCallback(() => {
+  const redo = useCallback((): PageDraftSnapshot | null => {
     flushDebounced();
     const next = futureRef.current[0];
-    if (!next) return false;
+    if (!next) return null;
     futureRef.current = futureRef.current.slice(1);
     pastRef.current = [...pastRef.current, snapshot];
     stableRef.current = next;
     setSnapshot(next);
     bump();
-    return true;
+    return next;
   }, [flushDebounced, snapshot]);
 
   const reset = useCallback(