[AWS::Bedrock::Agent] - [Coverage] - Multiple Missing Features

### Name of the resource

AWS::Bedrock::Agent

### Resource name

_No response_

### Description

Raising this issue for missing features already available through the AWS Console
- [x] [Memory](https://docs.aws.amazon.com/bedrock/latest/userguide/agents-configure-memory.html) (allows an agent to retain conversational contexts across multiple sessions and recall past actions and behaviors)
- [x] [Multi-agent collaboration](https://aws.amazon.com/blogs/aws/introducing-multi-agent-collaboration-capability-for-amazon-bedrock/) (allows this agent to delegate tasks to collaborator agent)
- [ ] [Default Prompt Routers Support ](https://docs.aws.amazon.com/bedrock/latest/userguide/prompt-routing.html)
- [x] [Custom Orchestration](https://docs.aws.amazon.com/bedrock/latest/userguide/agents-custom-orchestration.html)

### Other Details

_No response_

Start by reviewing the AWS::Bedrock::Agent coverage status and the linked Amazon Bedrock prompt routing documentation, focusing on Default Prompt Routers Support. The issue names no repository files, tests, or implementation entry points; done would require confirming the requested feature is covered and reflected in the resource support.

Written by the indexing model from the issue text.