fix: close PI-140 cutover gaps

Back up unknown legacy Agents, reconnect settled Conversation observation, remove remaining active repository residue, and restore the bundled Python verifier import.

tests/unit/agent-session-sync.test.ts

@@ -3,10 +3,12 @@ import type { RawMessage } from '@/types/chat';
 import {
   buildAgentSessionData,
   flushPendingAgentSessionSync,
+  queueCodingConversationSessionSync,
   queueAgentSessionSync,
   resetAgentSessionSyncForTests,
   sanitizeAgentSessionText,
 } from '@/lib/agent-session-sync';
+import { createProductSnapshot } from '../fixtures/coding-conversation-product-fixtures';
 
 const getAuthStateMock = vi.hoisted(() => vi.fn());
 const getProfileStateMock = vi.hoisted(() => vi.fn());
@@ -145,6 +147,79 @@ describe('local Agent session sync', () => {
     ]));
   });
 
+  it('uploads natural-language messages from the final product Conversation snapshot', async () => {
+    queueCodingConversationSessionSync({
+      ...createProductSnapshot('conversation-1'),
+      conversation: {
+        ...createProductSnapshot('conversation-1').conversation,
+        projectId: 'project-1',
+      },
+      nodes: [
+        {
+          kind: 'message',
+          id: 'user-1',
+          role: 'user',
+          status: 'complete',
+          blocks: [{ kind: 'text', id: 'user-text', text: '解释一下。', status: 'complete' }],
+        },
+        {
+          kind: 'message',
+          id: 'assistant-1',
+          role: 'assistant',
+          status: 'complete',
+          blocks: [
+            { kind: 'thinking', id: 'thought', text: '内部推理', status: 'complete' },
+            { kind: 'text', id: 'answer', text: '这是自然语言回答。', status: 'complete' },
+          ],
+        },
+      ],
+      run: {
+        status: 'idle',
+        runId: 'run-1',
+        settledAt: Date.parse('2026-08-24T08:00:00.000Z'),
+        terminalReason: 'completed',
+      },
+    });
+    await flushPendingAgentSessionSync();
+
+    expect(pushSessionDataMock).toHaveBeenCalledWith(
+      'user-a',
+      'access-token',
+      {
+        project_id: 'project-1',
+        session_id: 'conversation-1',
+        updated_at: '2026-08-24T08:00:00.000Z',
+        messages: [
+          { id: 'user-1', role: 'user', text: '解释一下。' },
+          { id: 'assistant-1', role: 'assistant', text: '这是自然语言回答。' },
+        ],
+      },
+    );
+  });
+
+  it('does not queue a product Conversation without assistant natural language', async () => {
+    const base = createProductSnapshot('conversation-1');
+    queueCodingConversationSessionSync({
+      ...base,
+      nodes: [{
+        kind: 'message',
+        id: 'assistant-1',
+        role: 'assistant',
+        status: 'complete',
+        blocks: [{ kind: 'thinking', id: 'thought', text: '内部推理', status: 'complete' }],
+      }],
+      run: {
+        status: 'idle',
+        runId: 'run-1',
+        settledAt: Date.parse('2026-08-24T08:00:00.000Z'),
+        terminalReason: 'completed',
+      },
+    });
+    await flushPendingAgentSessionSync();
+
+    expect(pushSessionDataMock).not.toHaveBeenCalled();
+  });
+
   it('never uploads a pending snapshot under a different authenticated account', async () => {
     queueAgentSessionSync('prj_1', 'ses_1', [
       { id: 'user-1', role: 'user', content: '账号 A 的问题' },