feat: Runtime Resource Control Plane Client

[Hweinstock]

Problem

The SDK's runtime module (BedrockAgentCoreApp) only handles running the agent server process. There is no client for the runtime control plane — customers cannot programmatically create, update, get, or delete agent runtimes or endpoints. The starter toolkit wraps bedrock-agentcore-control APIs (create_agent_runtime, get_agent_runtime_endpoint, etc.) with status polling, endpoint readiness checks, and aggregated status reporting. Without this, customers have no programmatic path to manage agent runtime resources outside the CLI.

Acceptance Criteria

• Customers can create, get, update, and delete agent runtimes
• Customers can get and delete agent runtime endpoints
• Create/update operations poll until the endpoint reaches READY status
• Customers can query aggregated status (runtime + endpoint + memory)
• Teardown deletes resources in correct order (endpoint → runtime)
• All functionality is verified via integration tests running in CI

Relevant Links

• BedrockAgentCoreClient
• launch_bedrock_agentcore()
• destroy_bedrock_agentcore()
• get_status()