feat: integrate pixel teacher presence and resilient classroom preview

tests/unit/coding-conversations-store.test.tsx

@@ -665,6 +665,64 @@ describe('coding Conversation store', () => {
     expect(store.getState().draftsByConversationId['conversation-a'].text).toBe('');
   });
 
+  it.each(['completed', 'aborted', 'failed'] as const)('settles an accepted prompt from its own %s run without a request-tagged history node', async (terminalReason) => {
+    const store = createCodingConversationStore({
+      submitPrompt: vi.fn(async (input) => acceptance(input.conversationId, input.clientRequestId)),
+      createId: ids(),
+    });
+    store.getState().applySnapshotEvent(snapshotEvent(snapshot('conversation-a')));
+    store.getState().setDraft('conversation-a', 'hello');
+    await store.getState().submitPrompt({ conversationId: 'conversation-a', mode: 'prompt' });
+    store.getState().setDraft('conversation-a', '我的游戏在哪里哦');
+    const settled = snapshot('conversation-a', 1, 1);
+    settled.run = { status: terminalReason === 'failed' ? 'error' : 'idle', runId: 'run-1', terminalReason, settledAt: 2_000 };
+    store.getState().applySnapshotEvent(snapshotEvent(settled));
+    expect(store.getState().requestsByConversationId['conversation-a']).toEqual({});
+    expect(selectCodingConversationSnapshot('conversation-a')(store.getState())?.nodes).toEqual(settled.nodes);
+    expect(store.getState().draftsByConversationId['conversation-a'].text).toBe('我的游戏在哪里哦');
+  });
+
+  it('settles a prompt when its terminal snapshot arrives before the HTTP acceptance', async () => {
+    const pending = deferred<PromptAcceptance>();
+    const store = createCodingConversationStore({ submitPrompt: vi.fn(() => pending.promise), createId: ids() });
+    store.getState().applySnapshotEvent(snapshotEvent(snapshot('conversation-a')));
+    store.getState().setDraft('conversation-a', 'hello');
+    const submission = store.getState().submitPrompt({ conversationId: 'conversation-a', mode: 'prompt' });
+    const settled = snapshot('conversation-a', 1, 1);
+    settled.run = { status: 'idle', runId: 'run-1', terminalReason: 'completed', settledAt: 2_000 };
+    store.getState().applySnapshotEvent(snapshotEvent(settled));
+    expect(store.getState().requestsByConversationId['conversation-a']['request-1'].status).toBe('pending');
+    store.getState().setDraft('conversation-a', '保留新的问题');
+    pending.resolve(acceptance('conversation-a', 'request-1'));
+    await submission;
+    expect(store.getState().requestsByConversationId['conversation-a']).toEqual({});
+    expect(selectCodingConversationSnapshot('conversation-a')(store.getState())?.nodes).toEqual(settled.nodes);
+    expect(store.getState().draftsByConversationId['conversation-a'].text).toBe('保留新的问题');
+  });
+
+  it('does not treat an old idle snapshot or a locally optimistic node in an unrelated patch as delivery evidence', async () => {
+    const pending = deferred<PromptAcceptance>();
+    const store = createCodingConversationStore({ submitPrompt: vi.fn(() => pending.promise), createId: ids() });
+    store.getState().applySnapshotEvent(snapshotEvent(snapshot('conversation-a')));
+    store.getState().setDraft('conversation-a', 'hello');
+    const submission = store.getState().submitPrompt({ conversationId: 'conversation-a', mode: 'prompt' });
+    const previous = snapshot('conversation-a', 1, 1);
+    previous.run = { status: 'idle', runId: 'previous-run', terminalReason: 'completed', settledAt: 1_000 };
+    store.getState().applySnapshotEvent(snapshotEvent(previous));
+    store.getState().applyPatchBatchEvent(patchEvent('conversation-a', 2, { op: 'worker.state', state: { status: 'ready', generation: 1 } }));
+    expect(store.getState().requestsByConversationId['conversation-a']['request-1'].status).toBe('pending');
+    pending.resolve(acceptance('conversation-a', 'request-1'));
+    await submission;
+    expect(store.getState().requestsByConversationId['conversation-a']['request-1']).toMatchObject({ status: 'accepted', runId: 'run-1' });
+    store.getState().applySnapshotEvent(snapshotEvent({ ...previous, cursor: { workerGeneration: 1, seq: 3 } }));
+    expect(store.getState().requestsByConversationId['conversation-a']['request-1'].status).toBe('accepted');
+    store.getState().applyPatchBatchEvent(patchEvent('conversation-a', 4, { op: 'run.state', run: { status: 'idle', runId: 'run-1' } }));
+    expect(store.getState().requestsByConversationId['conversation-a']['request-1'].status).toBe('accepted');
+    store.getState().applyPatchBatchEvent(patchEvent('conversation-a', 5, { op: 'run.state', run: { status: 'idle', runId: 'run-1', terminalReason: 'completed', settledAt: 2_000 } }));
+    expect(store.getState().requestsByConversationId['conversation-a']).toEqual({});
+    expect(selectCodingConversationSnapshot('conversation-a')(store.getState())?.nodes.some((node) => node.kind === 'message' && node.status === 'optimistic')).toBe(false);
+  });
+
   it('preserves the optimistic UI id when a reconnect snapshot is already durable', async () => {
     const store = createCodingConversationStore({
       getSnapshot: vi.fn(),