Merge remote-tracking branch 'origin/master' into xtr/identified-immutable-messages

# Conflicts:
#	.agents/notes/implemented/feature/2026-07-21-cross-session-references.i18n.yaml
#	packages/context/session-reference/README.i18n.yaml
#	packages/context/session-reference/README.md
#	packages/context/session-reference/README.zh.md
#	packages/context/session-reference/src/index.ts

packages/context/session-reference/src/index.ts

@@ -9,9 +9,9 @@ import { Context, Service } from 'cordis'
 import z from 'schemastery'
 import type { Agent } from '@deepseek-ai/dsh-agent'
 import { createUserMessage } from '@deepseek-ai/dsh-llm'
-import type { ContentBlock } from '@deepseek-ai/dsh-llm'
-import type { SessionId, UserMessage } from '@deepseek-ai/dsh-session'
-import type { SessionSurfaceSnapshot } from '@deepseek-ai/dsh-session-query'
+import type { ContentBlock, UserMessage } from '@deepseek-ai/dsh-llm'
+import type { SessionId } from '@deepseek-ai/dsh-session'
+import type { SessionSurfaceSnapshot, SessionTitleObservationResult } from '@deepseek-ai/dsh-session-query'
 import {
   DEFAULT_CANDIDATE_LIMIT,
   DEFAULT_MAX_REFERENCE_BYTES,
@@ -103,7 +103,7 @@ export class SessionReferenceService extends Service {
   /**
    * List reference candidates, ranked by working-directory affinity.
    * @param agent - target agent; self is excluded and its cwd drives ranking.
-   * @param query - optional case-insensitive session-id/cwd substring.
+   * @param query - optional case-insensitive session-id/cwd/title substring.
    * @param limit - optional positive result cap.
    * @param signal - optional cancellation boundary for host autocomplete teardown.
    * @returns candidates labeled by latest title or, when absent, session id.
@@ -120,27 +120,42 @@ export class SessionReferenceService extends Service {
     const needle = query.toLocaleLowerCase()
     const targetCwd = agent.session.header.cwd
     assertNotCancelled(signal)
-    const records = (await settleWithCancellation(this.ctx.sessionQuery.listSessions(), signal))
+    const records = (await settleWithCancellation(this.ctx.sessionQuery.listSessions(signal), signal))
       .filter(record => record.header.id !== agent.id)
-      .filter((record) => {
-        if (needle === '') return true
-        return record.header.id.toLocaleLowerCase().includes(needle)
-          || record.header.cwd?.toLocaleLowerCase().includes(needle) === true
-      })
       .map((record, index) => ({ record, index }))
-      .sort((a, b) => candidateRank(a.record.header.cwd, targetCwd) - candidateRank(b.record.header.cwd, targetCwd)
-        || a.index - b.index)
-      .slice(0, limit)
-    const titles = await settleWithCancellation(
-      Promise.all(records.map(({ record }) => this.ctx.sessionQuery.readTitle(record.header.id))),
+    const inspected = needle === ''
+      ? records
+        .sort((a, b) => candidateRank(a.record.header.cwd, targetCwd) - candidateRank(b.record.header.cwd, targetCwd)
+          || a.index - b.index)
+        .slice(0, limit)
+      : records
+    const observations = await settleWithCancellation(
+      this.ctx.sessionQuery.readTitleSnapshots(inspected.map(({ record }) => record.header.id), signal),
       signal,
     )
-    return records.map(({ record }, index) => ({
-      sessionId: record.header.id,
-      label: titles[index]?.title ?? record.header.id,
-      ...record.header.cwd === undefined ? {} : { cwd: record.header.cwd },
-      createdAt: record.header.createdAt,
-    }))
+    return inspected.map(({ record, index }, observationIndex) => {
+      const observation = observations[observationIndex] as SessionTitleObservationResult
+      return {
+        record,
+        index,
+        label: observation.status === 'fulfilled'
+          ? observation.value.title?.title ?? record.header.id
+          : record.header.id,
+      }
+    }).filter(({ record, label }) => {
+      if (needle === '') return true
+      return record.header.id.toLocaleLowerCase().includes(needle)
+        || record.header.cwd?.toLocaleLowerCase().includes(needle) === true
+        || label.toLocaleLowerCase().includes(needle)
+    }).sort((a, b) => candidateRank(a.record.header.cwd, targetCwd) - candidateRank(b.record.header.cwd, targetCwd)
+      || a.index - b.index)
+      .slice(0, limit)
+      .map(({ record, label }) => ({
+        sessionId: record.header.id,
+        label,
+        ...record.header.cwd === undefined ? {} : { cwd: record.header.cwd },
+        createdAt: record.header.createdAt,
+      }))
   }
 
   /**