Bugfix/visual jailbreak pause

[leondz]

Modality matching & selection isn't implemented in harnesses yet, so this plugin is disabled by default to avoid surprising UX when "all" is selected as a target. Also add docs

[leondz]

@jmartin-tech have you any idea what's causing this possible false negative test failure? the test only fails on the pull_request_target trigger and not the push trigger, and I can't replicate it locally. i've left the branch intact just in case.

[jmartin-tech]

The failures stopped when this PR merged, because pull_request_target runs in the context of the parent repository and the main branch which did not have the files required causing the failure. The trigger on pull_request_target should only apply to CLAAssistant so actions will need to be watched for a bit to determine why pull_request_target is executing the Garak pytest actions.