HTTP runtime gateway targets cannot configure schema for policy guardrails

从 --schema 选项的 CLI 验证和部署处理入手，然后跟踪 HTTP 运行时目标在 agentcore.json 中的表示方式。验证 schema 是否针对 http-runtime 被接受和验证、是否持久化到 agentcore.json、是否在 deploy 过程中传递，并确保策略允许的良性请求能够成功。

Description

AgentCore Gateway HTTP runtime targets support an optional API schema. However, AWS documentation states that HTTP runtime agents are required provide this schema when using guardrails.

The CLI exposes --schema for gateway targets, but currently rejects it for --type http-runtime. Consequently, users cannot configure policy guardrails correctly for HTTP runtime targets.

Steps to Reproduce

Reproduce --schema validation rejection

1. create HTTP runtime with a policy engine
2. Add an HTTP runtime target while passing --schema flag

Reproduce deploy failure

1. create HTTP runtime with a policy engine
2. Add an HTTP runtime target without passing --schema flag
3. Deploy the target and apply guardrail policies
4. Attempt to invoke the target

Expected Behavior

• The CLI should accept a schema for HTTP runtime targets
• benign requests permitted by policy should succeed

Actual Behavior

• CLI rejects --schema for HTTP runtime targets
• benign requests permitted by policy are rejected due to missing schema

CLI Version

No response

Operating System

macOS

Additional Context

• Accept and validate --schema for http-runtime in CLI
• persist schema source in agentcore.json
• persist schema through deploy