fix(agent): address initial review findings

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

@@ -144,10 +144,10 @@ export class ReactLoopAgent implements Agent {
   }
 
   private async admit(onTurnBoundary: boolean): Promise<Admission> {
-    if (this.phase.kind !== 'running') throw new Error()
+    if (this.phase.kind !== 'running') throw new Error(`agent "${this.id}": admit outside running phase`)
     const signal = this.phase.abort.signal
     const claimed = [...this.inbox.nextStep]
-    const outboxLength = this.inbox.nextStep.length
+    const outboxLength = claimed.length
     const queued = onTurnBoundary ? this.inbox.nextTurn[0] : undefined
     if (queued !== undefined) claimed.push(queued)
     if (claimed.length === 0) return { kind: 'empty' }
@@ -167,7 +167,7 @@ export class ReactLoopAgent implements Agent {
 
   /** Admitted input stays unowned until `turn/start` commits. */
   private async turn(): Promise<boolean> {
-    if (this.phase.kind === 'idle') throw new Error()
+    if (this.phase.kind === 'idle') throw new Error(`agent "${this.id}": turn without driver reservation`)
     const abort = this.phase.kind === 'collecting' ? this.phase.abort : new AbortController()
     const { signal } = abort
     const lastTurn = this.phase.kind === 'collecting' ? this.phase.lastTurn : this.phase.turn
@@ -227,7 +227,7 @@ export class ReactLoopAgent implements Agent {
   }
 
   private async step(): Promise<TurnEndReason | null> {
-    if (this.phase.kind !== 'running') throw new Error()
+    if (this.phase.kind !== 'running') throw new Error(`agent "${this.id}": step outside running phase`)
     const { turn, step, abort: { signal } } = this.phase
     signal.throwIfAborted()
     await this.loopCtx.serial(agentCarrier(this), 'agent/step', this, turn, step, signal)

packages/core/agent/src/inbox.ts

@@ -44,6 +44,9 @@ export class Inbox {
 
   /**
    * Apply standard splice semantics and durably record the normalized result.
+   * The durable event commits before the live projection mutates, so synchronous
+   * `session/event` observers see the pre-splice lists and can reconstruct the
+   * removed messages from the normalized coordinates.
    * @param target - pending list to mutate.
    * @param start - splice position.
    * @param deleteCount - maximum number of messages to remove.
@@ -59,12 +62,14 @@ export class Inbox {
     outcome?: 'admitted' | 'canceled',
   ): UserMessage[] {
     const inbox = this.state[target]
-    const offset = Math.trunc(start) || 0
+    const truncatedStart = Math.trunc(start)
+    const offset = Number.isNaN(truncatedStart) ? 0 : truncatedStart
     const actualStart = offset < 0
       ? Math.max(inbox.length + offset, 0)
       : Math.min(offset, inbox.length)
+    const truncatedDeleteCount = Math.trunc(deleteCount)
     const actualDeleteCount = Math.min(
-      Math.max(Math.trunc(deleteCount) || 0, 0),
+      Math.max(Number.isNaN(truncatedDeleteCount) ? 0 : truncatedDeleteCount, 0),
       inbox.length - actualStart,
     )
     if (actualDeleteCount === 0 && inserted.length === 0) return []

packages/core/agent/src/types.ts

@@ -264,7 +264,11 @@ declare module 'cordis' {
 
 declare module '@deepseek-ai/dsh-session' {
   interface SessionEventMap {
-    /** One normalized mutation of an agent's durable pending-message lists. */
+    /**
+     * One normalized mutation of an agent's durable pending-message lists.
+     * Live dispatch precedes projection mutation, so synchronous observers may
+     * read the pre-splice inbox to recover the removed messages.
+     */
     'agent/inbox/spliced': {
       target: InboxTarget
       start: number