Amazon Q app auto update leaves volumes mounted

### 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 15.7.1 (24G231)

### Expected behaviour

When Amazon Q app auto updates it should un-mount its volume once it is done.

### Actual behaviour

It seems it leaves mounted volumes on my system. I removed 20 volumes a while ago, now I have 4 volumes back:

```
ls /Volumes/ | grep Amazon
Amazon Q
Amazon Q 1
Amazon Q 2
Amazon Q 3
```

### Steps to reproduce

Just let the app update itself.

### Environment

```yaml

[q-details]
version = "1.17.1"
hash = "52301a3b0f81abff5ecde04a02481734c5c7ecc4"
date = "2025-09-30T22:25:33.521557Z (9d ago)"
variant = "full"

[system-info]
os = "macOS 15.7.1 (24G231)"
chip = "Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz"
total-cores = 8
memory = "32.00 GB"

[environment]
cwd = "/"
cli-path = "/"
os = "Mac"
shell-path = "/bin/zsh"
shell-version = "5.9"
terminal = "iTerm 2"
install-method = "unknown"

[env-vars]
PATH = "/Users/USER/.nvm/versions/node/v22.19.0/bin:/Users/USER/.local/bin:/Users/USER/.jenv/shims:/Users/USER/.jenv/bin:/Users/USER/.pyenv/shims:/usr/local/sbin:/Users/USER/tools/scripts:/usr/local/bin:/usr/local/opt/coreutils/libexec/gnubin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Users/USER/tools/java/maven/bin:/Users/USER/tools/java/gradle/bin:/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:/usr/local/go/bin:/Library/Frameworks/Mono.framework/Versions/Current/Commands:/Users/USER/.devops_apps/dc_env/.rust/.cargo/bin:/Applications/iTerm.app/Contents/Resources/utilities:/Users/USER/.local/bin:/Users/USER/.local/bin"
QTERM_SESSION_ID = "977e59e6ca854baeae2367fe477b9e02"
Q_SET_PARENT_CHECK = "1"
Q_TERM = "1.17.1"
SHELL = "/bin/zsh"
TERM = "xterm-256color"
__CFBundleIdentifier = "com.googlecode.iterm2"
```

Inizia riproducendo un aggiornamento automatico dell’app Amazon Q su macOS e verifica in che modo l’updater monta e rimuove i volumi in /Volumes. Conferma se gli aggiornamenti ripetuti lasciano voci come «Amazon Q 1». Il lavoro è completato quando un aggiornamento termina senza lasciare montati volumi Amazon Q obsoleti, con un test di regressione o una verifica documentata del comportamento di pulizia.

Scritto dal modello di indicizzazione a partire dal testo della issue.