round 1: implement bracket-first manual compaction

packages/goal/command-goal/tests/command-goal.spec.ts

@@ -42,6 +42,7 @@ function stubAgent(ctx: Context, id: string): { agent: Agent; session: Session }
     followup: () => {},
     steer: () => {},
     inject(input) { appendInjection(session, input) },
+    reserveTurnAdmission: () => undefined,
     cancel() { status = 'idle' },
     whenIdle() { return Promise.resolve() },
   }

packages/goal/goal/tests/goal.spec.ts

@@ -55,6 +55,7 @@ function stubAgentForSession(session: Session): StubAgent {
       if (shouldDefer) deferred.push(input)
       else appendInjection(session, input)
     },
+    reserveTurnAdmission: () => undefined,
     cancel() {},
     whenIdle() { return Promise.resolve() },
   }

packages/goal/goal/tests/projection.spec.ts

@@ -45,6 +45,7 @@ function liveAgent(ctx: Context, session: Session): Agent {
     inject(input: UserMessage) {
       session.append('user/message', input, { surfaceOp: 'append' })
     },
+    reserveTurnAdmission: () => undefined,
     cancel() {},
     whenIdle() { return Promise.resolve() },
   }

packages/goal/tool-goal/tests/tool-goal.spec.ts

@@ -39,6 +39,7 @@ function stubAgent(rawId: string, supplied?: Session): StubAgent {
     inject(input) {
       session.append('user/message', input, { surfaceOp: 'append' })
     },
+    reserveTurnAdmission: () => undefined,
     cancel() {},
     whenIdle() { return Promise.resolve() },
   }