refactor: co-locate security, storage, telemetry, tracking, worker tests
Move unit tests from tests/unit/ to internal/ following Go conventions:
Security tests:
- tests/unit/security/* -> internal/security/* (audit, config_integrity, filetype, gpu_audit, hipaa_validation, manifest_filename, path_traversal, resource_quota, secrets)
Storage tests:
- tests/unit/storage/* -> internal/storage/* (db, experiment_metadata)
Telemetry tests:
- tests/unit/telemetry/* -> internal/telemetry/* (telemetry)
Tracking tests:
- tests/unit/reproducibility/* -> internal/tracking/* (config_hash, environment_capture)
Worker tests:
- tests/unit/worker/* -> internal/worker/* (artifacts, config, hash_bench, plugins/jupyter_task, plugins/vllm, prewarm_v1, run_manifest_execution, snapshot_stage, snapshot_store, worker)
Update import paths in test files to reflect new locations.
61660dc925