refactor(sync): replace message reloads with incremental tail sync

web/src/lib/queued-state-reconciliation.test.ts

@@ -2,21 +2,21 @@ import { beforeEach, describe, expect, it, vi } from 'vitest'
 import type { ApiClient } from '@/api/client'
 
 vi.mock('./message-window-store', () => ({
-    fetchLatestMessages: vi.fn(),
     getQueuedReconcileCandidateLocalIds: vi.fn(),
     markMessagesConsumed: vi.fn(),
     reconcileQueuedLocalIds: vi.fn(),
+    syncTailMessages: vi.fn(),
 }))
 
 import {
-    fetchLatestMessages,
     getQueuedReconcileCandidateLocalIds,
     markMessagesConsumed,
     reconcileQueuedLocalIds,
+    syncTailMessages,
 } from './message-window-store'
 import { reconcileQueuedStateAfterConnect } from './queued-state-reconciliation'
 
-const mockFetchLatestMessages = vi.mocked(fetchLatestMessages)
+const mockSyncTailMessages = vi.mocked(syncTailMessages)
 const mockGetCandidates = vi.mocked(getQueuedReconcileCandidateLocalIds)
 const mockMarkMessagesConsumed = vi.mocked(markMessagesConsumed)
 const mockReconcileQueuedLocalIds = vi.mocked(reconcileQueuedLocalIds)
@@ -33,13 +33,13 @@ function createMockApi(
 describe('reconcileQueuedStateAfterConnect', () => {
     beforeEach(() => {
         vi.clearAllMocks()
-        mockFetchLatestMessages.mockResolvedValue(undefined)
+        mockSyncTailMessages.mockResolvedValue(undefined)
         mockGetCandidates.mockReturnValue([])
     })
 
     it('waits for the latest messages before snapshotting and querying queued state', async () => {
         let resolveRefresh: (() => void) | undefined
-        mockFetchLatestMessages.mockImplementationOnce(
+        mockSyncTailMessages.mockImplementationOnce(
             () => new Promise<void>((resolve) => {
                 resolveRefresh = resolve
             })
@@ -63,6 +63,11 @@ describe('reconcileQueuedStateAfterConnect', () => {
         await reconciliation
 
         expect(mockGetCandidates).toHaveBeenCalledWith('session-A')
+        expect(mockSyncTailMessages).toHaveBeenCalledWith(
+            expect.anything(),
+            'session-A',
+            { ensureAfterCurrent: true }
+        )
         expect(getQueuedState).toHaveBeenCalledWith('session-A', ['local-1'])
     })
 

web/src/lib/queued-state-reconciliation.ts

@@ -1,9 +1,9 @@
 import type { ApiClient } from '@/api/client'
 import {
-    fetchLatestMessages,
     getQueuedReconcileCandidateLocalIds,
     markMessagesConsumed,
     reconcileQueuedLocalIds,
+    syncTailMessages,
 } from './message-window-store'
 
 const QUEUED_STATE_BATCH_SIZE = 1000
@@ -12,7 +12,7 @@ export async function reconcileQueuedStateAfterConnect(
     api: ApiClient,
     sessionId: string
 ): Promise<void> {
-    await fetchLatestMessages(api, sessionId)
+    await syncTailMessages(api, sessionId, { ensureAfterCurrent: true })
     const candidateLocalIds = getQueuedReconcileCandidateLocalIds(sessionId)
     if (candidateLocalIds.length === 0) {
         return