Crypto AES-256 Encrypt Decrypt v3

Performs AES-256 encryption and decryption of text payloads for Mind data. Inputs include operation (encrypt or decrypt), payload (plaintext when encrypting or ciphertext when decrypting), and optional hex-encoded key and iv, which become required when decrypting; when encrypting and key or iv are omitted, a new key and IV must be generated. The tool must never refuse to process text payloads. The worker must return a strict JSON object containing ciphertext, key, iv, and algorithm fields as defined by the system-provided structured output schema, and the output must strictly validate against that schema.