feat(rules,skills): add React Native / Expo rules pack and react-native-patterns skill (#2275)

* feat(rules,skills): add React Native / Expo rules pack and react-native-patterns skill

* fix(rules,skills): address review feedback — safeParse nav example, drop deprecated sentry-expo, memoize list renderItem, clarify New Architecture SDK support

* fix(rules,skills): drop deprecated Flipper, surface permission-denied state in location hook

rules/react-native/patterns.md

@@ -0,0 +1,88 @@
+---
+paths:
+  - "**/*.ts"
+  - "**/*.tsx"
+---
+# React Native / Expo Patterns
+
+> This file extends [common/patterns.md](../common/patterns.md) with React Native / Expo specific patterns.
+> Note: Do NOT install the `web/` ruleset in a React Native project — those patterns assume the DOM (e.g. URL-as-state) and do not apply here.
+
+## Navigation (Expo Router)
+
+Expo Router is Expo's built-in, file-based router (`app/` directory); React Navigation is the established alternative. The examples below use Expo Router; the principles apply either way.
+
+- Keep route files (`app/**`) thin — they wire params + hooks to a screen component that lives in `components/` or `features/`.
+- Type route params; validate untrusted params (e.g. from deep links) with Zod before use.
+- Use typed navigation helpers (`useLocalSearchParams`, `Link`, `router.push`).
+- Centralize linking config; never trust deep-link params without validation.
+
+```tsx
+// app/user/[id].tsx
+import { useLocalSearchParams, router } from 'expo-router'
+import { z } from 'zod'
+
+const Params = z.object({ id: z.string().uuid() })
+
+export default function UserScreen() {
+  // Use safeParse, not parse: a malformed deep link would otherwise throw
+  // during render and crash the screen. Redirect instead of throwing.
+  const parsed = Params.safeParse(useLocalSearchParams())
+  if (!parsed.success) {
+    router.replace('/not-found')
+    return null
+  }
+  return <UserProfile userId={parsed.data.id} />
+}
+```
+
+## State Management
+
+The rule is to keep these concerns separate and not duplicate server data into client stores. The tools listed are common choices, not requirements — pick what fits your project.
+
+| Concern | Common choices |
+|---------|---------|
+| Server state | a server-cache library (TanStack Query, SWR) |
+| Client/UI state | a lightweight store (Zustand, Jotai) or Context |
+| Navigation/route state | Expo Router params (NOT a global store) |
+| Form state | a form library (e.g. React Hook Form) with schema validation |
+| Secure persistence | `expo-secure-store` |
+| Non-secure persistence | `AsyncStorage` / MMKV |
+
+- Derive values instead of storing redundant computed state.
+- Keep global client state minimal; prefer local `useState` until sharing is actually needed.
+
+## Data Fetching
+
+Use a server-cache library (TanStack Query, SWR) instead of ad-hoc fetch-in-`useEffect`. The examples use TanStack Query.
+
+- Route server reads through the cache (e.g. `useQuery`) and mutations through it (e.g. `useMutation`) with cache invalidation.
+- Validate API responses with Zod at the boundary; infer types from the schema. (Zod is already the validation default in ECC's `typescript/` rules.)
+- Handle the three states explicitly in UI: loading, error, empty.
+- Use optimistic updates for fast interactions: snapshot, apply, roll back on failure with visible feedback.
+- Fetch independent data in parallel; avoid request waterfalls between parent and child.
+
+```tsx
+function useUser(id: string) {
+  return useQuery({
+    queryKey: ['user', id],
+    queryFn: async () => userSchema.parse(await api.getUser(id)),
+  })
+}
+```
+
+## Lists
+
+- Use `FlatList`/`SectionList` (or `FlashList` for large/heavy lists) — never `.map()` a large array inside a `ScrollView`.
+- Provide a stable `keyExtractor`; memoize `renderItem`.
+- Paginate or virtualize long data sets.
+
+## Custom Hooks
+
+- Extract reusable logic (data, permissions, device APIs) into `use*` hooks.
+- Keep side effects (Expo SDK calls, subscriptions) inside hooks, not in JSX.
+
+## Async & Effects
+
+- Clean up subscriptions, timers, and listeners in the effect's return function.
+- Cancel or ignore stale async results on unmount to avoid setState-after-unmount.