Merge remote-tracking branch 'origin/worktree/session-format-04-live-assistant-stream' into worktree/session-format-05-v1-v2-chunk-migration

# Conflicts:
#	.agents/notes/implemented/architecture/2026-08-31-live-assistant-stream-frames.i18n.yaml
#	.agents/notes/implemented/architecture/2026-08-31-live-assistant-stream-frames.md
#	.agents/notes/implemented/architecture/2026-08-31-live-assistant-stream-frames.zh.md
#	.agents/notes/implemented/simplification/2026-08-06-buffer-free-feedback-telemetry.i18n.yaml
#	.agents/notes/implemented/simplification/2026-08-06-buffer-free-feedback-telemetry.md
#	.agents/notes/implemented/simplification/2026-08-06-buffer-free-feedback-telemetry.zh.md
#	apps/web/tests/scaffold.ts
#	docs/config-catalog.i18n.yaml
#	docs/config-catalog.md
#	docs/config-catalog.zh.md
#	packages/api/session-controller/README.i18n.yaml
#	packages/api/session-controller/README.md
#	packages/api/session-controller/README.zh.md
#	packages/api/session-controller/src/client/sessions/assistant-stream.ts
#	packages/core/agent-loop/src/agent.ts
#	packages/core/agent-loop/src/assistant-stream.ts
#	packages/core/agent-loop/tests/loop.spec.ts
#	packages/core/agent/src/runtime-types.ts
#	packages/session/session-telemetry/tests/telemetry.spec.ts
#	packages/test-support/llm-replay/README.i18n.yaml
#	packages/test-support/llm-replay/README.md
#	packages/test-support/llm-replay/README.zh.md
#	packages/test-support/llm-replay/src/alpha-refusal-fixtures.ts
#	packages/test-support/llm-replay/src/index.ts
#	packages/test-support/llm-replay/tests/llm-replay.spec.ts
#	packages/test-support/session-snapshot/README.i18n.yaml
#	packages/test-support/session-snapshot/README.md
#	packages/test-support/session-snapshot/README.zh.md
#	packages/test-support/session-snapshot/src/suite.ts
#	packages/test-support/session-snapshot/tests/suite.spec.ts
#	snapshots/sdk/sdk.snapshot.ts
#	snapshots/session/headless.snapshot.ts

packages/api/session-controller/src/client/sessions/assistant-stream.ts

@@ -101,6 +101,7 @@ export class ClientAssistantStream {
     this.durableCursor = Math.max(this.durableCursor, event.seq)
     this.transientInGap = 0
     if (this.attemptForSettlement(event) !== undefined) {
+      if (this.pending.has(event.seq)) return { type: 'rebaseline' }
       this.pending.set(event.seq, entry)
       return undefined
     }
@@ -115,6 +116,7 @@ export class ClientAssistantStream {
   acceptFrame(frame: SessionAssistantStreamFrame): ClientAssistantStreamResult {
     switch (frame.type) {
       case 'start':
+        if (this.activeAttempt !== undefined || this.pending.size > 0) return { type: 'rebaseline' }
         this.pending.clear()
         this.activeAttempt = {
           attemptId: String(frame.attemptId),
@@ -126,9 +128,11 @@ export class ClientAssistantStream {
         return undefined
       case 'chunk': {
         const attempt = this.activeAttempt
-        if (attempt === undefined
-          || attempt.attemptId !== String(frame.attemptId)
-          || frame.index !== attempt.nextIndex) return { type: 'rebaseline' }
+        // A controller mounted after the Host saw this attempt has no start
+        // frame to reconstruct. Its durable settlement publishes directly;
+        // ignore the transient suffix until the next known start.
+        if (attempt === undefined || attempt.attemptId !== String(frame.attemptId)) return undefined
+        if (frame.index !== attempt.nextIndex) return { type: 'rebaseline' }
         attempt.nextIndex += 1
         this.transientInGap += 1
         return {
@@ -151,10 +155,10 @@ export class ClientAssistantStream {
       }
       case 'end': {
         const attempt = this.activeAttempt
-        this.activeAttempt = undefined
         if (attempt === undefined || attempt.attemptId !== String(frame.attemptId)) {
-          return { type: 'rebaseline' }
+          return undefined
         }
+        this.activeAttempt = undefined
         if (frame.index !== attempt.nextIndex) return { type: 'rebaseline' }
         if (frame.outcome.kind === 'abandoned') {
           return this.pending.size === 0 ? undefined : { type: 'rebaseline' }
@@ -162,9 +166,7 @@ export class ClientAssistantStream {
         if (this.publishedSeqs.has(frame.outcome.seq)) return undefined
         const entry = this.pending.get(frame.outcome.seq)
         if (entry === undefined
-          || entry.event.type !== frame.outcome.eventType
-          || entry.event.data.turn !== attempt.turn
-          || entry.event.data.step !== attempt.step) {
+          || entry.event.type !== frame.outcome.eventType) {
           return { type: 'rebaseline' }
         }
         this.pending.delete(frame.outcome.seq)

packages/api/session-controller/src/index.ts

@@ -369,7 +369,8 @@ export class SessionController extends TypertRemoteService {
    * Follow one Session log from its opening or resume cursor.
    * @param request - durable address and last committed sequence already held by the caller.
    * @param signal - cancellation owned by the Remote stream carrier.
-   * @returns a complete opening snapshot followed by gap-free event frames.
+   * @returns a complete opening snapshot followed by gap-free durable event
+   *   frames and optional cursorless assistant-stream frames.
    */
   @Remote({ mode: 'stream' })
   follow(request: SessionFollowRequest, signal: AbortSignal): AsyncIterable<SessionFollowFrame> {

packages/api/session-controller/src/list.ts

@@ -145,8 +145,6 @@ export class ApiSessionList {
 
   private summarizeCold(header: SessionHeader): SessionSummary {
     const projections = this.projectionsFor(header, undefined)
-    const raced = this.ctx.sessions.get(header.id)
-    if (raced !== undefined) return this.summaryFor(raced)
     const metadata = projections?.values.sessionListMetadata
     return {
       sessionId: header.id,