Include subdirectory jailbreak templates in listings

[biefan]

Summary

• list jailbreak templates from the cached recursive template scan instead of only the top-level directory
• add regression coverage for subdirectory template discovery in both TextJailBreak and the AIRT jailbreak scenario

Problem

TextJailBreak already resolves template names from subdirectories such as pliny/amazon/nova.yaml, but get_jailbreak_templates() only scans templates/*.yaml at the top level.

This creates an inconsistent API surface: a template name can be loaded successfully via template_file_name, but the same name is missing from the advertised template list and is rejected by Jailbreak(..., jailbreak_names=[...]) validation.

Testing

• .venv/bin/pytest tests/unit/datasets/test_jailbreak_text.py tests/unit/scenarios/test_jailbreak.py -q