test(picklescan): cover startup hook source refresh

[mldangelo-oai]

Summary

• add a focused call-graph regression for startup hook file-open/file-write source rewrites
• verify rewritten module source is re-read instead of using stale clean cache state

Tests

• UV_CACHE_DIR=/tmp/modelaudit-uv-cache PROMPTFOO_DISABLE_TELEMETRY=1 uv run pytest packages/modelaudit-picklescan/tests/test_call_graph_import_statements.py::test_startup_hook_write_call_graph_refreshes_after_source_rewrite
• UV_CACHE_DIR=/tmp/modelaudit-uv-cache uv run ruff format modelaudit/ packages/modelaudit-picklescan/src packages/modelaudit-picklescan/tests tests/
• UV_CACHE_DIR=/tmp/modelaudit-uv-cache uv run ruff check --fix modelaudit/ packages/modelaudit-picklescan/src packages/modelaudit-picklescan/tests tests/
• UV_CACHE_DIR=/tmp/modelaudit-uv-cache uv run mypy modelaudit/ packages/modelaudit-picklescan/src packages/modelaudit-picklescan/tests tests/
• UV_CACHE_DIR=/tmp/modelaudit-uv-cache PROMPTFOO_DISABLE_TELEMETRY=1 uv run pytest -n auto -m "not slow and not integration" --maxfail=1

Note: the first full pytest attempt hit an unrelated load-sensitive timing assertion in tests/scanners/test_pytorch_zip_scanner.py::test_pytorch_zip_skips_numeric_data_files; that test passed in isolation and the full rerun passed.

[github-actions]

Workflow run and artifacts

Performance Benchmarks

Compared 12 shared benchmarks with a regression threshold of 15%.
Status: 0 regressions, 0 improved, 12 stable, 0 new, 0 missing.
Aggregate shared-benchmark median: 562.00ms -> 555.76ms (-1.1%).

Workload	Benchmark	Target	Size	Files	Baseline	Current	Change	Status
clean-training-checkpoint	tests/benchmarks/test_picklescan_benchmarks.py::test_picklescan_clean_training_checkpoint	safe_large	278.2 KiB	1	11.53ms	10.30ms	-10.6%	stable
suspicious-pickle-intake	tests/benchmarks/test_scan_benchmarks.py::test_scan_suspicious_pickle_intake	suspicious-intake	183.8 KiB	4	72.11ms	68.72ms	-4.7%	stable
padded-multi-stream-upload	tests/benchmarks/test_picklescan_benchmarks.py::test_picklescan_padded_multi_stream_upload	multi_stream_padded	4.1 KiB	1	398.1us	382.2us	-4.0%	stable
nested-payload-review	tests/benchmarks/test_picklescan_benchmarks.py::test_picklescan_nested_payload_review[nested_base64]	nested_base64	98 B	1	117.1us	120.6us	+3.0%	stable
nested-payload-review	tests/benchmarks/test_picklescan_benchmarks.py::test_picklescan_nested_payload_review[nested_hex]	nested_hex	130 B	1	128.0us	124.5us	-2.7%	stable
chunked-upload-stream	tests/benchmarks/test_picklescan_benchmarks.py::test_picklescan_chunked_upload_stream	chunked_stream	278.2 KiB	1	13.81ms	13.52ms	-2.1%	stable
direct-malicious-upload	tests/benchmarks/test_picklescan_benchmarks.py::test_picklescan_direct_malicious_upload	malicious_reduce	52 B	1	335.1us	328.9us	-1.8%	stable
single-checkpoint-preflight	tests/benchmarks/test_scan_benchmarks.py::test_scan_single_checkpoint_before_load	single_checkpoint.pkl	183.0 KiB	1	33.85ms	33.51ms	-1.0%	stable
nested-payload-review	tests/benchmarks/test_picklescan_benchmarks.py::test_picklescan_nested_payload_review[nested_raw]	nested_raw	78 B	1	114.4us	113.3us	-0.9%	stable
duplicate-heavy-registry	tests/benchmarks/test_scan_benchmarks.py::test_scan_duplicate_registry_snapshot	registry-snapshot	915.2 KiB	13	174.53ms	173.48ms	-0.6%	stable
warm-cache-rescan	tests/benchmarks/test_scan_benchmarks.py::test_scan_warm_cached_repository_rescan	release-candidate	547.3 KiB	32	30.29ms	30.39ms	+0.3%	stable
mixed-model-repository	tests/benchmarks/test_scan_benchmarks.py::test_scan_release_candidate_repository	release-candidate	547.3 KiB	32	224.79ms	224.77ms	-0.0%	stable