feat(orgchart): integrate chart-only viewport and scoped guard fixes

Add initial fit and direct wheel zoom with preserved default presentation. Integrate five scoped GuardFix findings and AI generation preselection policy. Exclude Cell experiments and retain five historical guard failures.

examples/org-chart-chart-only/react.html

@@ -0,0 +1,13 @@
+<!doctype html>
+<html lang="ko">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <link rel="icon" href="data:," />
+    <title>OrgChart Chart Only · React</title>
+  </head>
+  <body>
+    <div id="chart"></div>
+    <script type="module" src="./react.tsx"></script>
+  </body>
+</html>