test(probes): add unit tests for goodside probe module

[nuthalapativarun]

Add probe-unique tests for garak/probes/goodside.py.

Verification

• python -m pytest tests/probes/test_probes_goodside.py -v — all 6 tests pass

What is tested

WhoIsRiley

• Every prompt mentions "Riley Goodside" (validates the hallucination-check intent)
• primary_detector is goodside.RileyIsnt

ThreatenJSON

• Exactly one prompt is generated
• Prompt contains the JSON instruction and the threat clause ("innocent man") — the threatening language is the unique mechanism of this probe
• primary_detector is goodside.PlainJSON

Davidjl

• triggers list is parallel to prompts list (required for _attempt_prestore_hook to assign per-attempt triggers correctly)
• active is False (glitch-token probe is intentionally inactive)

Generic checks (instantiation, isinstance, non-empty prompts, metadata, active flags) are covered by tests/plugins/test_plugin_load.py.