[DO_NOT_MERGE] sync effect (V2) development and testing

src/vanilla.ts

@@ -1,7 +1,18 @@
 export { atom } from './vanilla/atom.ts'
 export type { Atom, WritableAtom, PrimitiveAtom } from './vanilla/atom.ts'
 
-export { createStore, getDefaultStore } from './vanilla/store.ts'
+export {
+  createStore,
+  getDefaultStore,
+  INTERNAL_buildStore,
+} from './vanilla/store.ts'
+
+export type {
+  INTERNAL_AtomState,
+  INTERNAL_DevStoreRev4,
+  INTERNAL_PrdStore,
+  INTERNAL_SecretStoreMethods,
+} from './vanilla/store.ts'
 
 export type {
   Getter,