Pin react to react-native's bundled renderer in Renovate (#26)

React asserts at runtime that `react` and the `react-native-renderer`
bundled inside react-native share an exact version, but react-native only
declares a loose peer range, so Renovate happily bumped react past the
renderer (19.2.7 vs 19.2.3) and the app crashed at launch. Renovate can't
see the bundled renderer version, so stop updating react/react-test-renderer
automatically — they're now bumped by hand alongside react-native. @types/react
splits out into its own group since it tracks the public API, not the renderer.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: dfalling

renovate.json

@@ -12,9 +12,14 @@
       "groupName": "react-native"
     },
     {
-      "description": "Group React and its companions — react-test-renderer is pinned to the React version",
-      "matchPackageNames": ["react", "react-test-renderer", "@types/react"],
-      "groupName": "react"
+      "description": "Do not bump react/react-test-renderer on their own — they must exactly match the react-native-renderer bundled in react-native. React asserts that equality at runtime, but react-native only declares a loose peer range (e.g. ^19.2.3), so Renovate would otherwise raise react past the bundled renderer and crash the app at launch (this happened: react 19.2.7 vs renderer 19.2.3). Renovate cannot read the bundled renderer version, so these are pinned and updated by hand together with the react-native upgrade.",
+      "matchPackageNames": ["react", "react-test-renderer"],
+      "enabled": false
+    },
+    {
+      "description": "@types/react tracks the public React API, not the bundled renderer, so it is safe to update on its own",
+      "matchPackageNames": ["@types/react"],
+      "groupName": "react-types"
     },
     {
       "description": "Group all GraphQL Codegen packages together",