MessagePack msgspec trigger PoC

• trigger_vector: [4, 2, 7]
• loader: msgspec.msgpack.decode(..., type=ModelState)
• control: control.msgpack
• malicious: trigger.msgpack

Local probe summary

• [4, 2, 7] -> control 0.0 / malicious 1.0
• [4, 2, 0] -> control 0.0 / malicious 0.0
• [1, 2, 7] -> control 0.0 / malicious 0.0
• [9, 9, 9] -> control 0.0 / malicious 0.0