Support Kiro permissions

[saitota]

Creating this issue to track implementation status. If you'd like this feature, please upvote with 👍.

Refs #832

• Docs: https://kiro.dev/docs/cli/chat/permissions/
• Agent config: https://kiro.dev/docs/cli/custom-agents/configuration-reference/
• Permissions schema PR: feat: add permissions schema definition and JSON Schema generation #1349