refactor(agent): simplify inbox-driven turn admission

packages/context/time-context/tests/time-context.spec.ts

@@ -42,14 +42,11 @@ function sessionAgent(session: Session, id = 'agent'): Agent {
     session,
     inbox: new Inbox(session, { inserted: () => {}, discarded: () => {} }),
     status: 'running',
-    acceptsNextStep: true,
     ctx: new Context(),
     send: () => {},
     followup: () => {},
     steer: () => {},
     inject: () => { throw new Error('time-context must append directly to the open step') },
-    updateInbox: () => 'not-found',
-    reserveTurnAdmission: () => undefined,
     cancel() {},
     whenIdle: () => Promise.resolve(),
   }
@@ -250,7 +247,7 @@ describe('durable step context', () => {
       surfaceOp: { op: 'replace', start: user.seq, end: reading.seq },
       sourceEventSeqs: [user.seq, reading.seq],
     })
-    original.append('turn/end', { turn: 1, reason: { kind: 'completed' } })
+    original.append('turn/end', { turn: 1, step: 0, reason: { kind: 'completed' } })
     expect(JSON.stringify(original.deriveMessages())).not.toContain('Time sampled while preparing')
 
     const resumed = new Session(SessionId('resumed'), [...original.events])
@@ -279,7 +276,7 @@ describe('durable step context', () => {
     const firstAgent = sessionAgent(first, 'first-agent')
     openMessageTurn(first, 1)
     await fire(ctx, firstAgent, 1, 1)
-    first.append('turn/end', { turn: 1, reason: { kind: 'completed' } })
+    first.append('turn/end', { turn: 1, step: 0, reason: { kind: 'completed' } })
 
     vi.setSystemTime(BASE + 500)
     openMessageTurn(first, 2)