feat(session): persist optional time zones

packages/session/session-persistence/tests/persistence.spec.ts

@@ -374,6 +374,28 @@ describe('PersistenceCoordinator bounded writes', () => {
 })
 
 describe('PersistenceCoordinator stored identity', () => {
+  it('rejects a non-string timeZone decoded by a backend', async () => {
+    const ctx = new Context()
+    await ctx.plugin(SessionStore)
+    const backend = new ControlledBackend()
+    const id = SessionId('invalid-stored-zone')
+    backend.store.set(id, {
+      meta: { ...meta(id), timeZone: 1 as unknown as string },
+      events: [],
+    })
+    let coordinator!: PersistenceCoordinator<never>
+    const fiber = await ctx.plugin(Object.assign((inner: Context) => {
+      coordinator = new PersistenceCoordinator(inner, backend)
+    }, { inject: ['sessions'] }))
+    try {
+      await expect(coordinator.inspect(id)).rejects.toThrow(/stored session .* timeZone must be a string/)
+      expect((coordinator as unknown as CoordinatorInternals).states.size).toBe(0)
+    } finally {
+      await fiber.dispose()
+      await ctx.fiber.dispose()
+    }
+  })
+
   it('rejects a mismatched backend header before repair or state publication', async () => {
     const ctx = new Context()
     await ctx.plugin(SessionStore)