fix: preserve image attachments in live and restored conversations

tests/e2e/pi-coding-first-chat.spec.ts

@@ -603,6 +603,23 @@ async function installCodingFirstChatHost(
           await new Promise<void>((resolve) => { state.releaseSnapshot = resolve; });
           state.snapshotPending = false;
         }
+        const posted = state.captured.find((request) => (
+          request.path === `/api/coding/conversations/${conversation.id}/prompt` && request.method === 'POST'
+        ));
+        if (!featureComplete && posted?.body) {
+          const refs = posted.body.attachments as Array<{ attachmentId: string }>;
+          return respond({ snapshot: {
+            ...snapshot,
+            nodes: [{ kind: 'message', id: 'entry:sent-image', sourceEntryId: 'sent-image',
+              role: 'user', status: 'complete', blocks: [
+                { kind: 'text', id: 'entry:sent-image:content:0', text: posted.body.text, status: 'complete' },
+                ...refs.map(({ attachmentId }, index) => ({
+                  kind: 'image', id: `entry:sent-image:image:${index}`, attachmentId, mime: 'image/png',
+                })),
+              ] }],
+            cursor: { workerGeneration: 1, seq: 1 },
+          } });
+        }
         const currentSnapshot = state.snapshotSettled
           ? {
               ...snapshot,
@@ -872,6 +889,20 @@ test('first PI Conversation is editable under 500 ms and submits before runtime
       { attachmentId: expect.any(String) },
     ]);
     expect(JSON.stringify(prompt?.body)).not.toContain('data:image');
+    await releaseSnapshot(electronApp);
+    const persistedMessage = page.locator('[data-node-id="entry:sent-image"]');
+    await expect(persistedMessage).toBeVisible();
+    await expect(persistedMessage.getByRole('img', { name: '对话图片附件' })).toBeVisible();
+    await expect(persistedMessage.getByRole('button', { name: '从这里创建新对话分支' })).toBeVisible();
+    // A full renderer reload discards its optimistic state and blob URLs.
+    await page.reload();
+    page = await getStableWindow(electronApp);
+    await expect.poll(async () => (await readState(electronApp)).snapshotPending).toBe(true);
+    await releaseSnapshot(electronApp);
+    await expect(page.locator('[data-node-id="entry:sent-image"]').getByRole('img', {
+      name: '对话图片附件',
+    })).toBeVisible();
+
   } finally {
     await releaseSnapshot(electronApp);
   }