bug: MCP server to aded to q-cli

### 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
- [x] I have run `q doctor` in the affected terminal session
- [x] I have run `q restart` and replicated the issue again

### Operating system

macos

### Expected behaviour

mcp server available in `/tools` list

### Actual behaviour

mcp.json is added to .amazonq/mcp.json according to https://github.com/awslabs/mcp/blob/main/src/aws-documentation-mcp-server/README.md

but q-cli does not see this config and is not adding to tools

```
> /tools

Current tool permissions:
- execute_bash Write-only commands [Default]
- report_issue Trusted [Default]
- use_aws Write-only commands [Default]
- fs_write Per-request [Default]
- fs_read Trusted [Default]
```

there should appear:

```
- awslabs.aws-documentation-mcp-server ___read_documentation
- awslabs.aws-documentation-mcp-server ___search_documentation
```

to be able use aws mcp when prompting

### Steps to reproduce

mcp.json is added to .amazonq/mcp.json according to https://github.com/awslabs/mcp/blob/main/src/aws-documentation-mcp-server/README.md

but q-cli does not see this config and is not adding to tools

```
> /tools

Current tool permissions:
- execute_bash Write-only commands [Default]
- report_issue Trusted [Default]
- use_aws Write-only commands [Default]
- fs_write Per-request [Default]
- fs_read Trusted [Default]
```

there should appear:

```
- awslabs.aws-documentation-mcp-server ___read_documentation
- awslabs.aws-documentation-mcp-server ___search_documentation
```

to be able use aws mcp when prompting

### Environment

```yaml
[q-details]
version = "1.7.3"
hash = "3e4ae79d371315e80ddac772b43fff2cba314104"
date = "2025-04-10T05:48:16.435186Z (1d ago)"
variant = "full"

[system-info]
os = "macOS 12.5.1 (21G83)"
total-cores = 4
memory = "16.00 GB"

[environment]
cwd = "/private/tmp/amazon-q-for-command-line"
cli-path = "/private/tmp/amazon-q-for-command-line"
os = "Mac"
shell-path = "/bin/zsh"
shell-version = "5.8"
terminal = "iTerm 2"
install-method = "brew"
```

Das Issue identifiziert .amazonq/mcp.json und den Befehl /tools; beginne damit, das Problem unter macOS 12.5.1 mit q 1.7.3 durch q doctor und q restart zu reproduzieren, und verfolge anschließend, wo die CLI die MCP-Konfiguration lädt und /tools befüllt. Als abgeschlossen gilt die Aufgabe, wenn die beiden aws-documentation MCP-Tools in der /tools-Liste erscheinen.

Vom Indexierungsmodell aus dem Issue-Text verfasst.