fix(desktop): keep attachment close and code copy icons visible (#95611)

* fix(desktop): keep attachment close and code copy icons visible

Hover-only opacity-0 hid the composer remove control and code-block copy button, so they stayed clickable but invisible on Windows and other no-hover surfaces.

* test(desktop): pin attachment close and code copy visibility at rest

The remove chip and code-block copy control must stay in the tree without a hover class, so Windows and no-hover surfaces cannot hide them again.

apps/desktop/src/app/chat/composer/attachments.test.tsx

@@ -236,6 +236,18 @@ describe('AttachmentList', () => {
     )
   })
 
+  it('shows the remove control at rest and does not hide it behind hover', async () => {
+    const onRemove = vi.fn()
+
+    await renderWithI18n(<AttachmentList attachments={[makeAttachment('a', 'doc.pdf')]} onRemove={onRemove} />)
+
+    const remove = screen.getByRole('button', { name: 'Remove doc.pdf' })
+
+    expect(remove.className.split(/\s+/)).not.toContain('opacity-0')
+    fireEvent.click(remove)
+    expect(onRemove).toHaveBeenCalledWith('a')
+  })
+
   it('still routes a non-image attachment to the preview rail', async () => {
     $previewTabs.set([])