fix: isolate attachment submission state

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

@@ -429,6 +429,55 @@ describe('coding Conversation store', () => {
       .toMatchObject({ id: 'node-1', status: 'error' });
   });
 
+  it('keeps attachment preparation failures out of runtime recovery and permits a direct retry', async () => {
+    const recover = vi.fn(async () => undefined);
+    const submitPrompt = vi.fn(async (input) => acceptance(
+      input.conversationId,
+      input.clientRequestId,
+    ));
+    const store = createCodingConversationStore({
+      getSnapshot: vi.fn(),
+      openEvents: vi.fn(),
+      submitPrompt,
+      recover,
+      createId: ids(),
+    });
+    store.getState().applySnapshotEvent(snapshotEvent(snapshot('conversation-a')));
+    store.getState().setDraft('conversation-a', 'Inspect the image');
+
+    await expect(store.getState().submitPrompt({
+      conversationId: 'conversation-a',
+      mode: 'prompt',
+      prepareAttachments: async () => {
+        throw new AppError('VALIDATION', '图片附件无效。', undefined, {
+          backendCode: 'CODING_ATTACHMENT_INVALID',
+        });
+      },
+    })).rejects.toThrow('图片附件无效。');
+
+    expect(store.getState().entriesByConversationId['conversation-a']).toMatchObject({
+      loadState: 'live',
+      error: null,
+    });
+    expect(store.getState().draftsByConversationId['conversation-a'].text)
+      .toBe('Inspect the image');
+    expect(store.getState().requestsByConversationId['conversation-a']['request-1'])
+      .toMatchObject({ status: 'rejected', errorCode: 'CODING_ATTACHMENT_INVALID' });
+    expect(submitPrompt).not.toHaveBeenCalled();
+    expect(recover).not.toHaveBeenCalled();
+
+    await store.getState().submitPrompt({
+      conversationId: 'conversation-a',
+      mode: 'prompt',
+      prepareAttachments: async () => [{
+        attachmentId: 'attachment-valid',
+        mime: 'image/png',
+        previewUrl: 'blob:valid',
+      }],
+    });
+    expect(submitPrompt).toHaveBeenCalledOnce();
+  });
+
   it('keeps an uncertain optimistic request recoverable without replaying it on reconnect', async () => {
     const source = new FakeEventSource();
     const submitPrompt = vi.fn(async () => {