Move _setup_file_logging() from module import to create_app() so
importing headroom.proxy.server in tests or library contexts no longer
silently attaches a RotatingFileHandler to the user's live proxy.log.
This was discovered via PR #303: running the test suite produced
"Optimization failed: TimeoutError" entries in ~/.headroom/logs/proxy.log
because TestClient instantiations from test_proxy_anthropic_compression_diagnostics.py
inherited the module-level handler.
Add a regression test that imports the server module in a subprocess
and asserts no RotatingFileHandler is attached to the headroom logger.
Refs #303 (review thread).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Tests for jitter_delay_ms helper, asyncio.timeout shim, release workflow
--allow-same-version flag validation, SIGKILL fallback on Windows, and
LatencyHistogram from the repro harness script.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>