feat: Add Crucible agentic challenge attack notebook (#333)

* feat: Add agentic AI red teaming attack notebook

Demonstrates automated adversarial attacks (TAP, GOAT, Crescendo) against
Crucible agentic challenges (toolshed, webwhisper, vaultguard) using the
AIRT framework with diverse transforms and real-time console output.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: Strip notebook outputs to pass pre-commit checks

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: rdheekonda