Failed to send the request: An unknown error occurred: AccessDeniedException

### 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 26.2.0 (25C56)

### Expected behaviour

Normal response from kiro cli

### Actual behaviour

> are you ok?

Kiro is having trouble responding right now:
0: Failed to send the request: An unknown error occurred: AccessDeniedException
1: An unknown error occurred: AccessDeniedException
2: unhandled error (AccessDeniedException)
3: service error
4: unhandled error (AccessDeniedException)
5: Error { code: "AccessDeniedException", message: "The bearer token included in the request is invalid.", aws_request_id: "5ee49022-fe68-4e59-9199-34a6f44cf141" }

Location:
crates/chat-cli/src/cli/chat/mod.rs:1440

Backtrace omitted. Run with RUST_BACKTRACE=1 environment variable to display it.
Run with RUST_BACKTRACE=full to include source snippets.

### Steps to reproduce

> are you ok?

Kiro is having trouble responding right now:
0: Failed to send the request: An unknown error occurred: AccessDeniedException
1: An unknown error occurred: AccessDeniedException
2: unhandled error (AccessDeniedException)
3: service error
4: unhandled error (AccessDeniedException)
5: Error { code: "AccessDeniedException", message: "The bearer token included in the request is invalid.", aws_request_id: "5ee49022-fe68-4e59-9199-34a6f44cf141" }

Location:
crates/chat-cli/src/cli/chat/mod.rs:1440

Backtrace omitted. Run with RUST_BACKTRACE=1 environment variable to display it.
Run with RUST_BACKTRACE=full to include source snippets.

### Environment

```yaml
lalsanmo@c889f3ec94ef ~ % q diagnostic
Warning! Q CLI is now Kiro CLI and should be invoked as kiro-cli rather than q

[q-details]
version = "1.24.1"
hash = "ffce156030f05d9cec3d4817c3a64245a967db74"
date = "2026-01-27T20:48:19.714341Z (6d ago)"
variant = "full"

[system-info]
os = "macOS 26.2.0 (25C56)"
chip = "Apple M1 Pro"
total-cores = 8
memory = "16.00 GB"

[environment]
cwd = "/Users/USER"
cli-path = "/Users/USER"
os = "Mac"
shell-path = "/bin/bash"
shell-version = "3.2.57"
terminal = "macOS"
install-method = "unknown"

[env-vars]
PATH = "/Users/USER/.nvm/versions/node/v20.18.2/bin:/opt/local/bin:/opt/local/sbin:/opt/homebrew/bin:/opt/homebrew/sbin:/Library/Frameworks/Python.framework/Versions/2.7/bin:/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:/opt/pmk/env/global/bin:/Library/TeX/texbin:/Users/USER/.local/bin:/Users/USER/.local/bin:/Users/USER/bin:/Applications/CMake.app/Contents/bin:/Applications/SEGGER/JLINK:/Applications/Commander.app/Contents/MacOS:/usr/local/bin/mergehex:/Users/USER/.toolbox/bin:/Users/USER/.toolbox/bin:/Users/USER/.local/bin"
QTERM_SESSION_ID = "2c78a6132147432eaf130bd3c3e86f3e"
Q_SET_PARENT_CHECK = "1"
Q_TERM = "1.24.1"
SHELL = "/bin/zsh"
TERM = "xterm-256color"
__CFBundleIdentifier = "com.apple.Terminal"
```