test(agent-team): remove an unused store from checkpoint restoration

The cold checkpoint regression calls only the projection registry register and restore methods. Neither needs SessionStore, so mounting and disposing that extra service obscured the fixture dependency. Keep the registry lifecycle and the recovered-content assertion unchanged.

packages/experimental/agent-team/tests/projection-events.spec.ts

@@ -355,10 +355,8 @@ describe('Agent Teams projection events', () => {
 
   it('rebuilds lossy version-3 Team checkpoints from the original log', async () => {
     const ctx = new Context()
-    const store = ctx.plugin(SessionStore)
     const registry = ctx.plugin(SessionProjectionRegistry)
     try {
-      await store
       await registry
       ctx.sessionProjections.register(teamProjectionDefinition)
       const extension = JSON.parse('{"type":"plugin/custom","__proto__":{"saved":true}}') as ContentBlock
@@ -379,7 +377,6 @@ describe('Agent Teams projection events', () => {
       expect(state.messages[0]?.content).toEqual([extension])
     } finally {
       await registry.dispose()
-      await store.dispose()
     }
   })