perf(native-chat): the recovering open reads the journal once

Every conversation open now goes through the recovering open, including the
read restore of every chat at startup, which used to replay its journal once.
The recovering open replayed it twice: once to probe it and again inside the
open. The probe is now handed to the open as its load.

src/main/native-chat/agent-session-wire/agent-session-journal-recovery.test.ts

@@ -6,14 +6,14 @@
 import { mkdtemp, rm, writeFile } from 'node:fs/promises'
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
-import { afterEach, beforeEach, describe, expect, it } from 'vitest'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 import type {
   AgentJournalItemIdentity,
   AgentSessionJournalIdentity
 } from '../../../shared/agent-session-journal-types'
 import { openJournalDatabase } from '../agent-session-journal/journal-database'
 import { JOURNAL_DB_SCHEMA_VERSION } from '../agent-session-journal/journal-database-schema'
-import { loadJournal } from '../agent-session-journal/journal-open'
+import { loadJournal, replayJournal } from '../agent-session-journal/journal-open'
 import { journalDatabaseFile } from '../agent-session-journal/journal-paths'
 import { readJournalEpochRows } from '../agent-session-journal/journal-row-table'
 import { createTrackedJournalOpener } from '../agent-session-journal/journal-store-test-open'
@@ -24,6 +24,12 @@ import {
   recoveryJournalDir
 } from './agent-session-journal-recovery'
 
+// Only the store's own replay goes through the mock; the probe's, inside the same module, does not.
+vi.mock('../agent-session-journal/journal-open', async (importOriginal) => {
+  const actual = await importOriginal<{ replayJournal: typeof replayJournal }>()
+  return { ...actual, replayJournal: vi.fn(actual.replayJournal) }
+})
+
 const CODEX_SESSION = '019fd532-7c11-7a90-b6de-4e1a2c3d5f60'
 
 const IDENTITY: AgentSessionJournalIdentity = {
@@ -160,6 +166,21 @@ describe('openAgentSessionJournalWithRecovery', () => {
     expect(opened.snapshot().items).toHaveLength(2)
   })
 
+  it('reads the journal once: the probe is the open', async () => {
+    await seedJournal(2)
+    vi.mocked(replayJournal).mockClear()
+    const opened = journals.track(
+      await openAgentSessionJournalWithRecovery({
+        identity: IDENTITY,
+        journalDir,
+        fence: 1,
+        historyFilePath
+      }).then((result) => result.journal)
+    )
+    expect(opened.snapshot().items).toHaveLength(2)
+    expect(replayJournal).not.toHaveBeenCalled()
+  })
+
   it('rebuilds a holed journal in place on a fresh epoch', async () => {
     await seedJournal(3)
     await deleteRow(3)

src/main/native-chat/agent-session-wire/agent-session-journal-recovery.ts

@@ -67,7 +67,9 @@ export async function openAgentSessionJournalWithRecovery(input: {
   }
   const journal = await openAgentSessionJournal({
     identity: input.identity,
-    journalDir: input.journalDir
+    journalDir: input.journalDir,
+    // The probe is this open's replay; omitted, not `null`, when there was nothing to load.
+    ...(probe ? { loaded: probe } : {})
   })
   if (!probe?.corrupt) {
     return { journal, recovery: null }