[Feature Request] CLI Support for User-Defined Customizations

### Checks

- [x] I have searched [github.com/aws/amazon-q-developer-cli/issues](https://github.com/aws/amazon-q-developer-cli/issues?q=) and there are no duplicates of my issue

### Operating system

macOS 15.5.0 (24F74)

### Expected behaviour

Our company has developed a customization for Amazon Q Developer, and we would like to be able to select and use it. However, this does not currently seem possible, unlike with the VSCode plugin

### Actual behaviour

```
[chat-transcript]
> How to configure the CLI so that it can use the customization created by my company?

To configure the CLI to use customizations created by your company, you'll typically need to set up organizational or enterprise-specific configurations. Here are the common approaches:

## For AWS CLI with organizational customizations:

**1. Configure custom endpoints or profiles:**
\```bash
# Set up a named profile for your organization
aws configure --profile company-profile

# Or configure custom endpoints if your company uses private AWS endpoints
aws configure set endpoint_url https://your-company-aws-endpoint.com --profile company-profile
\```

**2. Use environment variables for company-specific settings:**
\```bash
export AWS_PROFILE=company-profile
export AWS_CONFIG_FILE=/path/to/company/aws/config
export AWS_SHARED_CREDENTIALS_FILE=/path/to/company/aws/credentials
\```

## For Amazon Q CLI with company customizations:

**1. Check if your company has provided specific configuration:**
\```bash
q --help
q configure --help
\```

**2. Set up company-specific profiles or endpoints:**
\```bash
# If your company uses a custom Q endpoint
q configure set endpoint https://your-company-q-endpoint.com

# Or set up authentication for company resources
q configure set auth-method company-sso
\```

**3. Use company-provided configuration files:**
- Your company may have provided specific config files
- Place them in the appropriate config directory (usually `~/.aws/` or `~/.q/`)

## General steps:

1. **Contact your company's cloud/DevOps team** - they should provide:
- Specific configuration instructions
- Custom endpoints or authentication methods
- Required certificates or credentials

2. **Check for company documentation** - look for internal wikis or documentation about CLI setup

3. **Verify company-specific MCP servers** - if your company uses custom MCP servers, you may need to configure them

Would you like me to help you with a specific type of customization, or do you have particular configuration files or endpoints that your company has provided?
[Tool uses: none]

> /issue

I can help you report an issue or make a feature request! I have a tool that can open a pre-filled GitHub issue template for you.
[Tool uses: report_issue]
```

### Steps to reproduce

_No response_