Merge remote-tracking branch 'origin/feat/send-unify' into xtr/agent-loop-message-machine

# Conflicts:
#	.agents/notes/implemented/architecture/2026-07-22-unified-send-and-coalesced-user-messages.i18n.yaml
#	.agents/notes/implemented/architecture/2026-07-22-unified-send-and-coalesced-user-messages.md
#	.agents/notes/implemented/architecture/2026-07-22-unified-send-and-coalesced-user-messages.zh.md
#	docs/architecture.i18n.yaml
#	docs/architecture.md
#	docs/architecture.zh.md
#	docs/core-data-structures/core.md
#	packages/context/session-reference/README.md
#	packages/cordis/tool-cordis/src/api-catalog.ts
#	packages/core/agent-loop/README.md
#	packages/core/agent-loop/src/agent.ts
#	packages/core/agent-loop/src/inbox.ts
#	packages/core/agent-loop/tests/agent.spec.ts
#	packages/core/agent-loop/tests/cancel.spec.ts
#	packages/core/agent-loop/tests/contract-regressions.spec.ts
#	packages/core/agent-loop/tests/coverage-edges.spec.ts
#	packages/core/agent-loop/tests/interception.spec.ts
#	packages/core/agent-loop/tests/loop.spec.ts
#	packages/core/agent/README.md
#	packages/core/agent/src/types.ts
#	packages/core/agent/tests/agent.spec.ts
#	packages/ui/acp/src/index.ts
#	packages/ui/tui/src/index.ts
#	packages/ui/tui/tests/harness.ts

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

@@ -7,7 +7,7 @@ import type { GoalView } from '@deepseek-ai/dsh-goal'
  * Render the complete goal-round instruction retained in session history.
  * @param goal - exact active goal revision being admitted.
  * @param round - next positive round number.
- * @returns a fresh one-block prompt for `Agent.send()`.
+ * @returns a fresh one-block prompt for `Agent.followup()`.
  */
 export function renderGoalRoundPrompt(goal: GoalView, round: number): ContentBlock[] {
   return [{

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

@@ -276,7 +276,7 @@ describe('same-session goal driving', () => {
       ? Promise.resolve({ kind: 'block', reason: 'stop this round' })
       : next())
     test.ctx.on('goal/changed', (agent, change) => {
-      if (change.operation === 'block') agent.send([{ type: 'text', text: 'inspect the blocker' }])
+      if (change.operation === 'block') agent.followup([{ type: 'text', text: 'inspect the blocker' }])
     })
     test.ctx.goals.create(test.agent, { objective: 'stop and inspect' })
 
@@ -323,7 +323,7 @@ describe('same-session goal driving', () => {
   it('lets already-queued human work finish before reserving the next round', async () => {
     const test = await harness([textResponse('human answer'), textResponse('goal answer')])
     test.ctx.goals.create(test.agent, { objective: 'continue after the human', maxGoalRounds: 1 })
-    test.agent.send([{ type: 'text', text: 'human goes first' }])
+    test.agent.followup([{ type: 'text', text: 'human goes first' }])
 
     await waitForGoal(test.ctx, test.agent, goal => goal?.phase === 'blocked')
 
@@ -364,7 +364,7 @@ describe('same-session goal driving', () => {
     test.ctx.on('agent/inbox/enqueue', (agent, info) => {
       if (agent !== test.agent || info.source.kind !== 'goal' || inserted) return
       inserted = true
-      agent.send([{ type: 'text', text: 'human joined the pending batch' }])
+      agent.followup([{ type: 'text', text: 'human joined the pending batch' }])
     })
     test.ctx.goals.create(test.agent, { objective: 'yield to nested human input', maxGoalRounds: 1 })
 
@@ -479,16 +479,16 @@ describe('same-session goal driving', () => {
     expect(injectedTurn).toBeGreaterThan(goalTurn)
   })
 
-  it('blocks the goal when a custom agent rejects the otherwise valid send', async () => {
+  it('blocks the goal when a custom agent rejects the otherwise valid follow-up', async () => {
     const test = await harness([])
-    // inject shares send, so reject only the round send (a goal-sourced
-    // next-turn item), not the goal state-change injection that precedes it.
-    const realSend = test.agent.send.bind(test.agent)
-    vi.spyOn(test.agent, 'send').mockImplementation((content, options) => {
-      if (options?.source?.kind === 'goal' && (options.target ?? 'next-turn') === 'next-turn') {
+    // Reject only the goal-sourced round follow-up, not the state-change injection
+    // that precedes it.
+    const realFollowup = test.agent.followup.bind(test.agent)
+    vi.spyOn(test.agent, 'followup').mockImplementation((content, options) => {
+      if (options?.source?.kind === 'goal') {
         throw new Error('queue rejected')
       }
-      return realSend(content, options)
+      return realFollowup(content, options)
     })
     test.ctx.goals.create(test.agent, { objective: 'handle queue failure' })
 
@@ -502,15 +502,15 @@ describe('same-session goal driving', () => {
     expect(test.adapter.requests).toHaveLength(0)
   })
 
-  it('preserves a custom agent side effect when send disarms before throwing', async () => {
+  it('preserves a custom agent side effect when followup disarms before throwing', async () => {
     const test = await harness([])
-    const realSend = test.agent.send.bind(test.agent)
-    vi.spyOn(test.agent, 'send').mockImplementation((content, options) => {
-      if (options?.source?.kind === 'goal' && (options.target ?? 'next-turn') === 'next-turn') {
+    const realFollowup = test.agent.followup.bind(test.agent)
+    vi.spyOn(test.agent, 'followup').mockImplementation((content, options) => {
+      if (options?.source?.kind === 'goal') {
         test.ctx.goals.disarm(test.agent)
         throw new Error('queue rejected after disarm')
       }
-      return realSend(content, options)
+      return realFollowup(content, options)
     })
     test.ctx.goals.create(test.agent, { objective: 'preserve the newer activation state' })
 
@@ -621,7 +621,7 @@ describe('same-session goal driving', () => {
 
   it('does not invent goal state when ordinary queued work is cancelled', async () => {
     const test = await harness([])
-    test.agent.send([{ type: 'text', text: 'cancel ordinary work' }])
+    test.agent.followup([{ type: 'text', text: 'cancel ordinary work' }])
     test.agent.cancel({ kind: 'user' })
     await test.agent.whenIdle()
 
@@ -631,7 +631,7 @@ describe('same-session goal driving', () => {
 
   it('disarms without durably pausing when cancellation belongs to unrelated human work', async () => {
     const test = await harness(['hang'])
-    test.agent.send([{ type: 'text', text: 'inspect something first' }])
+    test.agent.followup([{ type: 'text', text: 'inspect something first' }])
     await waitForRequests(test.adapter, 1)
     const created = test.ctx.goals.create(test.agent, { objective: 'continue after inspection' })
 

packages/goal/tool-goal/README.md

@@ -18,7 +18,7 @@ An autonomous goal round that successfully reports `complete` or `blocked` contr
 
 Execution requires the exact live `exec.agent`, its inherited `AgentRegistry` initiator, running status, and an open turn. Create, edit, pause, and resume additionally require an accepted `{ kind: 'user' }` message or steering event in a runtime-root agent's current turn. Durable fork lineage does not demote a resumed root; live subagent ownership does.
 
-`{ kind: 'user' }` is a host attestation. `Agent.send()` and `steer()` assign it when their caller omits a source, so plugins, schedulers, and other non-human producers must pass their own source rather than inheriting human authority.
+`{ kind: 'user' }` is a host attestation. `Agent.followup()` and `steer()` assign it when their caller omits a source, so plugins, schedulers, and other non-human producers must pass their own source rather than inheriting human authority.
 
 Complete and blocked also accept the exact current goal round: a goal-sourced `user/message` whose id, revision, and round equal the folded current goal. A goal-round blocked call is mechanically rejected until `blockedAfterConsecutiveRounds`; the model judges whether the same condition actually persisted and must describe it in `blocked_reason`. Direct human authority may stop a goal immediately.
 

packages/goal/tool-goal/src/authority.ts

@@ -64,7 +64,7 @@ export function goalToolExecution(ctx: Context, exec: ToolRunContext): GoalToolE
 
 /**
  * Whether host-attested human input appears in the current root-agent turn.
- * An omitted `Agent.send()` / `steer()` source resolves to `user`, so non-human
+ * An omitted `Agent.followup()` / `steer()` source resolves to `user`, so non-human
  * producers must supply their own source rather than inheriting this authority.
  */
 function hasDirectHumanInput(ctx: Context, execution: GoalToolExecution): boolean {