fix(app): reflow iPad chat text after pane resize (#5716)

The selectable UIKit text view was a sibling of the Fabric content container, so existing chat rows kept an old width after Explorer changed the available pane. Make the container own the text view and preserve layout notifications on bounds changes. Includes a native geometry regression.

scripts/postinstall-patches.mjs

@@ -12,6 +12,10 @@ const patchedPackages = [
     nodeModulesPath: "node_modules/react-native-markdown-display",
     patchPrefix: "react-native-markdown-display+",
   },
+  {
+    nodeModulesPath: "node_modules/react-native-uitextview",
+    patchPrefix: "react-native-uitextview+",
+  },
   // Remove after react-native-unistyles ships
   // https://github.com/jpudysz/react-native-unistyles/pull/1203.
   {