[liuyinchu]

CallbackFileWrapper._close skips its cleanup when the cache callback raises. A cache write error or interruption therefore leaves the temporary file open and the callback attached; reading EOF again can call it again.

Run the existing callback-reference and temporary-file cleanup in finally. Keep the original exception propagation and callback data unchanged. Add tests using real http.client.HTTPResponse objects for empty/nonempty bodies, successful callbacks, OSError, and KeyboardInterrupt.

Validation on Linux, CPython 3.12.14:

• Original implementation: four new regressions fail, two controls pass.
• Final full suite: 122 passed, rerun against current master before submission.
• Repository Ruff/mypy lint, changed-file format, wheel/sdist build and strict Sphinx build pass.
• A localhost requests/urllib3 consumer with a failing cache backend confirms file closure/unlink and preserved error cause.

This is deliberately narrow: a retained traceback can still hold the existing mmap view. Native Windows/macOS and the other Python versions have not been tested locally.

AI disclosure: prepared with OpenAI Codex assistance, including a separate automated review and consumer probe. No human manual review is claimed.