refactor(agent): publish agent/inbox/claimed from Inbox.claim

Move the claimed-message notification loop out of the loop's pre-step
into Inbox.claim(target, turn), so the step-boundary operation publishes
its own claimed notifications like insertions and discards do.

packages/core/agent-loop/src/agent.ts

@@ -81,6 +81,7 @@ export class ReactLoopAgent implements Agent {
     this.inbox = new Inbox(session, {
       inserted: (message) => { emitAgentEvent(loopCtx, this, 'agent/inbox/inserted', { message }) },
       discarded: (message) => { emitAgentEvent(loopCtx, this, 'agent/inbox/discarded', { message }) },
+      claimed: (message, turn) => { emitAgentEvent(loopCtx, this, 'agent/inbox/claimed', { message, turn }) },
     })
     const lastTurn = session.events.findLast(event => event.type === 'turn/start')?.data.turn ?? 0
     this.phase = { kind: 'idle', lastTurn }
@@ -198,10 +199,7 @@ export class ReactLoopAgent implements Agent {
     /* v8 ignore next -- private callers establish the running phase before proposing a step */
     if (this.phase.kind !== 'running') throw new Error(`agent "${this.id}": pre-step outside running phase`)
     const signal = this.phase.abort.signal
-    const claimed = this.inbox.claim(target)
-    for (const message of claimed) {
-      emitAgentEvent(this.loopCtx, this, 'agent/inbox/claimed', { message, turn: position.turn })
-    }
+    const claimed = this.inbox.claim(target, position.turn)
     const assembly = await this.loopCtx.systemPrompt.assemble(assembleContextFor(this, signal))
     signal.throwIfAborted()
     const context = this.runtimeContext.project(renderContextSnapshot(assembly))

packages/core/agent/src/inbox.ts

@@ -19,6 +19,8 @@ export interface InboxNotifications {
   inserted(message: UserMessage): void
   /** Publish one discarded message. */
   discarded(message: UserMessage): void
+  /** Publish one claimed message inside its owning turn. */
+  claimed(message: UserMessage, turn: number): void
 }
 
 /** A replay-once projection that incrementally consumes later inbox splices. */
@@ -61,17 +63,19 @@ export class Inbox {
   }
 
   /**
-   * Remove and return the complete batch proposed for one step. The durable
-   * splices are pure deletions; the caller publishes claimed notifications.
+   * Remove and return the complete batch proposed for one step, publishing
+   * each claimed message. The durable splices are pure deletions.
    * @param target - whether this boundary also consumes one queued turn.
+   * @param turn - turn that will own the claimed batch.
    * @returns next-step input followed by the queued turn, when requested.
    * @internal - the agent loop's step-boundary operation, not a plugin seam.
    */
-  claim(target: InboxTarget): UserMessage[] {
+  claim(target: InboxTarget, turn: number): UserMessage[] {
     const claimed = this.mutate('next-step', 0, this.nextStep.length, [], false)
     if (target === 'next-turn') {
       claimed.push(...this.mutate('next-turn', 0, 1, [], false))
     }
+    for (const message of claimed) this.notifications.claimed(message, turn)
     return claimed
   }
 

packages/core/agent/tests/agent.spec.ts

@@ -22,7 +22,7 @@ function stubAgent(rawId: string, overrides: Partial<Agent> = {}): Agent {
     id,
     options: {},
     session,
-    inbox: new Inbox(session, { inserted: () => {}, discarded: () => {} }),
+    inbox: new Inbox(session, { inserted: () => {}, discarded: () => {}, claimed: () => {} }),
     status: 'idle',
     ctx: new Context(),
     send: () => {},
@@ -45,7 +45,7 @@ describe('Inbox', () => {
       inserted: [],
     })
 
-    expect(() => new Inbox(session, { inserted: () => {}, discarded: () => {} }))
+    expect(() => new Inbox(session, { inserted: () => {}, discarded: () => {}, claimed: () => {} }))
       .toThrow('invalid persisted inbox splice at session seq 0')
   })
 
@@ -54,6 +54,7 @@ describe('Inbox', () => {
     const inserted: UserMessage[] = []
     const discarded: UserMessage[] = []
     const inbox = new Inbox(session, {
+      claimed: () => {},
       inserted: message => void inserted.push(message),
       discarded: message => void discarded.push(message),
     })
@@ -92,7 +93,7 @@ describe('Inbox', () => {
 
   it('normalizes splice coordinates, rejects duplicate identities, and reports missing removals', () => {
     const session = Session.create(SessionId('splice-inbox'))
-    const inbox = new Inbox(session, { inserted: () => {}, discarded: () => {} })
+    const inbox = new Inbox(session, { inserted: () => {}, discarded: () => {}, claimed: () => {} })
     const first = createUserMessage({
       content: [{ type: 'text', text: 'first' }],
       source: { kind: 'user' },
@@ -113,6 +114,7 @@ describe('Inbox', () => {
     const session = Session.create(SessionId('clear-inbox'))
     const discarded: UserMessage[] = []
     const inbox = new Inbox(session, {
+      claimed: () => {},
       inserted: () => {},
       discarded: message => void discarded.push(message),
     })