Shipped: Multi-Agent Steganographic Prompt Injection Defense

Proof-of-concept that shows how a malicious instruction hidden in an image (LSB steganography) can be extracted and executed by a multi-agent system. Uses a Coordinator + 4 Workers + Verifier architecture over real MCP tools, with a local Qwen model driving agent decisions. Demonstrates a vulnerable path (stego-extracted text treated as trusted) and a protected path (source tagging + policy blocking of critical tools). Includes before/after visualization of the cover image and an email-attachment attack scenario.