fix(goal-session): discriminate plugin turn triggers

packages/goal/goal-session/README.md

@@ -21,7 +21,7 @@ The plugin has no tunable configuration. `maxGoalRounds` belongs to the goal def
 
 When an exact live agent is idle with an active, armed goal and remaining capacity, the driver first checkpoints pending goal mutations, then reserves `roundsStarted + 1` for the current `{ goalId, revision }`. It queues one `<goal_round>` prompt with `GoalMessageSource`. Admission through `agent/prompt-submit` verifies the complete queued record and current goal both before and after downstream prompt hooks; only the accepted `user/message` increments `roundsStarted`. A reservation rejected as stale does not consume the round number.
 
-One goal round owns one ordinary session turn, and that turn may contain several model/tool steps. Human messages remain ordinary turns and do not consume the goal cap. If human work enters the inbox before a reservation or joins its pending batch, automatic work yields until that work settles; a pending automatic prompt in a mixed batch is rejected and re-reserved only after the agent becomes idle.
+One goal round owns one ordinary session turn, and that turn may contain several model/tool steps. The driver pairs a reservation only with a `message` turn carrying its exact `GoalMessageSource`; merge-extensible plugin turn triggers do not admit or replace that reservation. Human messages remain ordinary turns and do not consume the goal cap. If human work enters the inbox before a reservation or joins its pending batch, automatic work yields until that work settles; a pending automatic prompt in a mixed batch is rejected and re-reserved only after the agent becomes idle.
 
 The retained prompt names the JSON-quoted objective and `round/maxGoalRounds`, treats the current workspace, tool results, and durable session state as authoritative, requires evidence before completion, and tells the model to leave the goal active when work remains. Quoting preserves multiline or tag-like objective text as data. Goal lifecycle mutations still require the independent authority checks in `dsh-tool-goal`.
 

packages/goal/goal-session/src/index.ts

@@ -345,11 +345,17 @@ export function apply(ctx: Context): void {
       switch (event.type) {
         case 'turn/start':
           state.openTurn = event.data.turn
-          if (state.attempt !== undefined && isGoalRoundSource(event.data.trigger.source)
-          && sameRound(event.data.trigger.source, state.attempt)) {
-            state.attempt.turn = event.data.turn
+          switch (event.data.trigger.kind) {
+            case 'message':
+              if (state.attempt !== undefined && isGoalRoundSource(event.data.trigger.source)
+              && sameRound(event.data.trigger.source, state.attempt)) {
+                state.attempt.turn = event.data.turn
+              }
+              return
+            default:
+              // Injection and merge-extensible plugin triggers cannot admit a queued goal message.
+              return
           }
-          return
         case 'user/message':
           if (state.attempt !== undefined && isGoalRoundSource(event.data.source)
           && sameRound(event.data.source, state.attempt)) {

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

@@ -12,6 +12,13 @@ import { SessionId } from '@deepseek-ai/dsh-session'
 import type { TurnEndReason } from '@deepseek-ai/dsh-session'
 import * as goalSession from '../src/index.ts'
 
+declare module '@deepseek-ai/dsh-session' {
+  interface TurnTriggerMap {
+    /** Test-only plugin turn with no message source. */
+    'test-metadata': { kind: 'test-metadata' }
+  }
+}
+
 type ScriptEntry = StreamChunk[] | Error | 'hang' | ((options: GenerateOptions) => StreamChunk[])
 
 /** Small request-recording adapter with controllable failure and cancellation. */
@@ -323,6 +330,31 @@ describe('same-session goal driving', () => {
     expect(requestText(test.adapter.requests[1]!)).toContain('<goal_round>')
   })
 
+  it('ignores plugin-owned turn triggers while a goal round is queued', async () => {
+    const test = await harness([textResponse('goal answer')])
+    const warnings: string[] = []
+    test.ctx.logger.warn = ((message: unknown) => { warnings.push(String(message)) }) as typeof test.ctx.logger.warn
+    let inserted = false
+    test.ctx.on('agent/queued', (agent, _content, info) => {
+      if (agent !== test.agent || info.source.kind !== 'goal' || inserted) return
+      inserted = true
+      const lastStart = agent.session.events.findLast(event => event.type === 'turn/start')
+      const turn = (lastStart?.data.turn ?? 0) + 1
+      agent.session.append('turn/start', {
+        turn,
+        trigger: { kind: 'test-metadata' },
+      })
+      agent.session.append('turn/end', { turn, reason: { kind: 'completed' } })
+    })
+    test.ctx.goals.create(test.agent, { objective: 'ignore metadata', maxGoalRounds: 1 })
+
+    await waitForGoal(test.ctx, test.agent, goal => goal?.phase === 'blocked')
+
+    expect(inserted).toBe(true)
+    expect(test.adapter.requests).toHaveLength(1)
+    expect(warnings.some(warning => warning.includes('session/event listener threw'))).toBe(false)
+  })
+
   it('makes a reserved round stale when a listener queues human work behind it', async () => {
     const test = await harness([textResponse('human batch'), textResponse('later goal')])
     let inserted = false