Refactor project name from "Open Claude Design" to "Open Design"

- Updated project name in package.json, package-lock.json, and README files.
- Changed CLI commands and references from "ocd" to "od".
- Adjusted file structure references in documentation and code to reflect new naming conventions.
- Enhanced .gitignore to include new runtime data files.
- Updated metadata in LICENSE file to match new project name.

src/components/FileViewer.tsx

@@ -155,7 +155,7 @@ function HtmlViewer({
       const data = ev?.data as
         | { type?: string; active?: number; count?: number }
         | null;
-      if (!data || data.type !== 'ocd:slide-state') return;
+      if (!data || data.type !== 'od:slide-state') return;
       if (typeof data.active !== 'number' || typeof data.count !== 'number') return;
       setSlideState({ active: data.active, count: data.count });
     }
@@ -166,7 +166,7 @@ function HtmlViewer({
   function postSlide(action: 'next' | 'prev' | 'first' | 'last') {
     const win = iframeRef.current?.contentWindow;
     if (!win) return;
-    win.postMessage({ type: 'ocd:slide', action }, '*');
+    win.postMessage({ type: 'od:slide', action }, '*');
   }
 
   // Keyboard nav on the host, so the user can press ←/→ even when focus