Unable to log in with device flow

### 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

Linux 6.1.163-186.299.amzn2023.x86_64 - Amazon Linux 2023.7.20250623

### Expected behaviour

I expect to get a URL and a device code that I can confirm in my browser.

### Actual behaviour

```
% kiro-cli login --use-device-flow --verbose
✔ Select login method · Use with Pro license
✔ Enter Start URL · [my start URL]
✔ Enter Region · us-east-1
error:
0: service error
1: InvalidRequestException
2: InvalidRequestException

Location:
crates/q_cli/src/cli/user.rs:518
```

### Steps to reproduce

See above

### Environment

```yaml

[q-details]
version = "2.0.0"
hash = "0026b0505ef7bc2b10780c7bdb57813e5d949747"
date = "2026-04-13T09:05:27.989221Z (3d ago)"
variant = "minimal"

[system-info]
chip = "Intel(R) Xeon(R) Platinum 8488C"
total-cores = 4
memory = "30.82 GB"

[system-info.os.linux]
kernel_version = "6.1.163-186.299.amzn2023.x86_64"
id = "amzn"
name = "Amazon Linux"
pretty_name = "Amazon Linux 2023.7.20250623"
version_id = "2023"
version = "2023"

[environment]
cwd = "/home/USER"
cli-path = "/home/USER"
os = "Linux"
shell-path = "/shared/toolbox/tools/toolbox/1.1.3790.0/toolbox-exec"
shell-version = "5.9"
install-method = "toolbox"

[env-vars]
PATH = "/home/USER/bin:/home/USER/.local/share/mise/installs/java/corretto-21.0.10.7.1/bin:/home/USER/.local/share/mise/installs/ruby/3.4.9/bin:/home/USER/.local/bin:/rtcw/bin:/home/USER/.sandbox-brazilcli/bin:/home/USER/.toolbox/bin:/home/USER/.aim/mcp-servers:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
TERM = "xterm-256color"
```