expo-sqlite shared-prepared-statement corruption repro

Minimal reproduction for https://github.com/expo/expo — expo-sqlite@57.0.2.

Two reads issued concurrently over one prepared statement (prepareAsync) corrupt each other's result sets: one reader's getAllAsync() steps rows bound by another reader's run. step/getAll/reset don't take the per-statement lock that run does, and getAllAsync() is a second native call after run's await, so the per-call lock cannot cover a cursor's run -> getAll pair.

Run

npm install
npx expo run:ios --configuration Release

Release embeds the JS bundle, so no Metro is needed. The repro is in App.tsx.

Observed (iPhone 17 Pro sim, iOS 26, expo-sqlite 57.0.2, RN 0.86.3, Release)

SERIALIZED  A(a/1)=["A1"]  B(b/1)=["B1"]
CONCURRENT  {"a/1":["A1"],"a/2":["A2","B3"],"a/3":["A3","B3"],"b/1":["B1","B3"],"b/2":["B2","B3"],"b/3":["B3","B3"]}
RESULT: CORRUPTED — 5/6 reads wrong

Each read that should return a single row gets another reader's row ("B3") leaked in. The serialized control is correct.

Root cause (shipped source)

• android/src/main/java/expo/modules/sqlite/SQLiteModule.kt: run wraps reset+bind+step in synchronized(statement) ("stateful … critical section for thread safety"); step/getAll/reset take no lock.
• ios/SQLiteModule.swift: identical — run takes statement.lock; step/getAll/reset take none.