diff --git a/.project-docs/30-worklog/tasks/20260823-pi-chat-timeline-c8f31a62.md b/.project-docs/30-worklog/tasks/20260823-pi-chat-timeline-c8f31a62.md
index 253fb89b..46a8106a 100644
--- a/.project-docs/30-worklog/tasks/20260823-pi-chat-timeline-c8f31a62.md
+++ b/.project-docs/30-worklog/tasks/20260823-pi-chat-timeline-c8f31a62.md
@@ -156,7 +156,8 @@
   acceptance settle, so removal or a next-message paste cannot mutate the
   captured image set. Attachment preparation failures now remain local to the
   Composer, restore the draft, permit direct retry without runtime recovery,
-  and retain already uploaded variants for reuse. Attachment route failures use
+  retain already uploaded variants for reuse, and wait for every concurrent
+  upload flight to settle before releasing the edit lock. Attachment route failures use
   only registered `CODING_ATTACHMENT_INVALID`, `CODING_ATTACHMENT_NOT_FOUND`,
   and `CODING_STORAGE_WRITE_FAILED` codes while preserving 413/404 status.
 - Synchronized `README.md` with the current Pi core Chat, first-Conversation,
diff --git a/src/pages/Chat/CodingChatPanel.tsx b/src/pages/Chat/CodingChatPanel.tsx
index 318ac28d..f4b7f52e 100644
--- a/src/pages/Chat/CodingChatPanel.tsx
+++ b/src/pages/Chat/CodingChatPanel.tsx
@@ -392,7 +392,10 @@ export function CodingChatPanel({
         };
       }
     });
-    await Promise.all(workers);
+    const results = await Promise.allSettled(workers);
+    for (const result of results) {
+      if (result.status === 'rejected') throw result.reason;
+    }
     return prepared;
   }, []);
 
diff --git a/tests/unit/coding-chat-panel.test.tsx b/tests/unit/coding-chat-panel.test.tsx
index d2f6c11c..f43a4a3a 100644
--- a/tests/unit/coding-chat-panel.test.tsx
+++ b/tests/unit/coding-chat-panel.test.tsx
@@ -365,7 +365,7 @@ describe('CodingChatPanel first Conversation', () => {
     expect(maxActiveUploads).toBeLessThanOrEqual(4);
   });
 
-  it('locks attachment removal while an upload is still pending', async () => {
+  it('keeps attachment removal locked until every upload settles after one fails', async () => {
     const upload = deferred<{ attachmentId: string; mime: string; byteLength: number }>();
     projectApi.list.mockResolvedValue({ projects: [project], activeProjectId: project.id });
     projectApi.config.mockResolvedValue({ project, config });
@@ -383,7 +383,11 @@ describe('CodingChatPanel first Conversation', () => {
       runId: 'run-1',
       mode: input.mode,
     }));
-    attachmentApi.upload.mockReturnValue(upload.promise);
+    attachmentApi.upload.mockImplementation((file: File) => (
+      file.name === 'failed.png'
+        ? Promise.reject(new Error('图片附件无效。'))
+        : upload.promise
+    ));
     const { CodingChatPanel } = await import('@/pages/Chat/CodingChatPanel');
     const { createLocalConversationSnapshot } = await import('@/pages/Chat/coding-chat-snapshot');
     const { codingConversationStore } = await import('@/stores/coding-conversations');
@@ -393,21 +397,24 @@ describe('CodingChatPanel first Conversation', () => {
     await waitFor(() => expect(codingConversationStore.getState().selectedConversationId)
       .toBe(conversation.id));
 
-    const file = new File(['image'], 'held.png', { type: 'image/png' });
+    const failed = new File(['failed'], 'failed.png', { type: 'image/png' });
+    const held = new File(['held'], 'held.png', { type: 'image/png' });
     fireEvent.change(screen.getByTestId('coding-file-attachment-input'), {
-      target: { files: [file] },
+      target: { files: [failed, held] },
     });
     fireEvent.click(await screen.findByRole('button', { name: '发送' }));
-    await waitFor(() => expect(attachmentApi.upload).toHaveBeenCalledOnce());
+    await waitFor(() => expect(attachmentApi.upload).toHaveBeenCalledTimes(2));
 
     const remove = screen.getByRole('button', { name: '移除图片 held.png' });
     expect(remove).toBeDisabled();
     fireEvent.click(remove);
     expect(screen.getByAltText('held.png')).toBeInTheDocument();
+    expect(screen.queryByText('图片附件无效。')).not.toBeInTheDocument();
 
     upload.resolve({ attachmentId: 'attachment-held', mime: 'image/png', byteLength: 5 });
-    await waitFor(() => expect(conversationApi.submit).toHaveBeenCalledOnce());
-    await waitFor(() => expect(screen.queryByAltText('held.png')).not.toBeInTheDocument());
+    expect(await screen.findByText('图片附件无效。')).toBeInTheDocument();
+    expect(remove).toBeEnabled();
+    expect(conversationApi.submit).not.toHaveBeenCalled();
   });
 
   it('keeps next-message images out of a submission while its 202 response is pending', async () => {