Test automatic request compression for JSON and raw bodies

[augrclk]

The compression suite covers forcing deflate with two --compress flags and skipping a small body with one flag. It does not currently exercise the normal case where one flag compresses a body because the result is smaller.

This adds end-to-end JSON and raw-body cases over both HTTP and HTTPS. They check that the server receives Content-Encoding: deflate, that decompression restores the original payload, and that Content-Length equals the compressed byte count. No production code or CLI behavior changes.

Validation on Python 3.12.14 / macOS 26.6.1:

• python -m pytest tests/test_compress.py -q: 20 passed, including the four new cases.
• Full suite: 1020 passed, 3 failed, 5 skipped, 4 xfailed. The failures are the existing test_naked_invocation error-text expectation and the two Big5 charset-detection cases. All three failures were reproduced from an unchanged archive of baseline 5b604c3 in the same environment.
• Full configured flake8 check: passed.
• git diff --check: passed.

Prepared and tested with assistance from OpenAI Codex. I added my name to AUTHORS.md as suggested by CONTRIBUTING.md.