Harden the support-ticket prompt

A support workflow uses this Amazon Bedrock Prompt Management request to classify inbound tickets. The current prompt is vague, returns free-form text, and lets instructions written inside a ticket influence routing. That makes automated queue selection unreliable and allows a customer message to masquerade as a system instruction.

Repair prompt-request.json for reliable routing to exactly one of BILLING, ACCESS, or DELIVERY.

• Wire the runtime input ticket_text into the template once, isolate it as untrusted data, and exclude its embedded instructions from the routing decision.
• Require only JSON with category and reason; limit generation to 120 tokens and temperature 0.2.
• Preserve the prompt identity, production variant, and model.