feat(renderer): editor buffer content feeds preview store (300ms debounce)

src/renderer/components/editor/EditorPane.tsx

@@ -1,9 +1,16 @@
+import { useEffect } from 'react';
 import { CodeMirrorEditor } from './CodeMirrorEditor';
 import { useEditorStore } from '@/stores/editor-store';
+import { usePreviewStore } from '@/stores/preview-store';
 
 export function EditorPane() {
   const { buffers, activeId } = useEditorStore();
   const buf = activeId ? buffers.get(activeId) : null;
+  const setPreviewSource = usePreviewStore((s) => s.setSource);
+
+  useEffect(() => {
+    if (buf) setPreviewSource(buf.content);
+  }, [buf?.id, buf?.content, buf, setPreviewSource]);
 
   if (!buf) {
     return (
@@ -22,4 +29,4 @@ export function EditorPane() {
       />
     </div>
   );
-}
+}