mcp servers are not loading: awslabs.core-mcp-server and awslabs.cost-analysis-mcp-server

### 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 26.0.1 (25A362)

### Expected behaviour

(base) terryfernandez@GC5KF2DWK7 Downloads % q chat
✗ awslabs.core-mcp-server has failed to load after 1.24 s
- Mcp error: -32002: connection closed: initialize response
- run with Q_LOG_LEVEL=trace and see $TMPDIR/qlog/qchat.log for detail
✓ awslabs.cdk-mcp-server loaded in 3.66 s
✓ awslabs.aws-documentation-mcp-server loaded in 3.79 s
✗ awslabs.cost-analysis-mcp-server has failed to load after 4.14 s
- Mcp error: -32002: connection closed: initialize response
- run with Q_LOG_LEVEL=trace and see $TMPDIR/qlog/qchat.log for detail
✓ awslabs.bedrock-kb-retrieval-mcp-server loaded in 4.37 s
✓ awslabs.nova-canvas-mcp-server loaded in 4.54 s

### Actual behaviour

when starting q chat: I get this error:
(base) terryfernandez@GC5KF2DWK7 Downloads % q chat
✗ awslabs.core-mcp-server has failed to load after 1.24 s
- Mcp error: -32002: connection closed: initialize response
- run with Q_LOG_LEVEL=trace and see $TMPDIR/qlog/qchat.log for detail
✓ awslabs.cdk-mcp-server loaded in 3.66 s
✓ awslabs.aws-documentation-mcp-server loaded in 3.79 s
✗ awslabs.cost-analysis-mcp-server has failed to load after 4.14 s
- Mcp error: -32002: connection closed: initialize response
- run with Q_LOG_LEVEL=trace and see $TMPDIR/qlog/qchat.log for detail
✓ awslabs.bedrock-kb-retrieval-mcp-server loaded in 4.37 s
✓ awslabs.nova-canvas-mcp-server loaded in 4.54 s

### Steps to reproduce

restart q chat

### Environment

```yaml

[q-details]
version = "1.17.1"
hash = "b0ef39f91625c36c2ed6f065628e7165fae9012c"
date = "2025-09-30T22:01:25.726592Z (15h ago)"

[system-info]
os = "macOS 26.0.1 (25A362)"
chip = "Apple M1 Pro"
total-cores = 10
memory = "16.00 GB"

[environment]
cwd = "/Users/USER/Downloads"
cli-path = "/Users/USER/Downloads"
install-method = "unknown"

[env-vars]
PATH = "/Users/USER/Downloads/google-cloud-sdk/bin:/Users/USER/.codeium/windsurf/bin:/opt/anaconda3/bin:/opt/anaconda3/condabin:/opt/homebrew/opt/krb5/sbin:/opt/homebrew/opt/krb5/bin:/Users/USER/.pyenv/shims:/usr/local/sbin:/usr/local/sbin:/opt/homebrew/bin:/opt/homebrew/sbin:/usr/local/bin:/System/Cryptexes/App/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin:/Library/Apple/usr/bin:/usr/local/share/dotnet:~/.dotnet/tools:/Users/USER/.local/bin"
QTERM_SESSION_ID = "d8a16fa89b34497caf613a7625ba99b5"
Q_SET_PARENT_CHECK = "1"
Q_TERM = "1.17.1"
SHELL = "/bin/zsh"
TERM = "xterm-256color"
__CFBundleIdentifier = "com.apple.Terminal"
```

Reproduziere den Fehler mit q restart, führe dann den Vorgang mit Q_LOG_LEVEL=trace aus und untersuche $TMPDIR/qlog/qchat.log auf Details zur initialize-Antwort. Als erledigt gilt dies, wenn awslabs.core-mcp-server und awslabs.cost-analysis-mcp-server in q chat erfolgreich geladen werden, ohne den connection-closed-Fehler.

Vom Indexierungsmodell aus dem Issue-Text verfasst.