Unable to save chat

### 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 15.5.0 (24F74)

### Expected behaviour

Be able to save chat by `/save .` Does it mean my chat history conclude something can't be serialized in json file?

### Actual behaviour

```
[default-agent] > /save .

Failed to export to .: Session paths are not serialized
```

### Steps to reproduce

_No response_

### Environment

```yaml

[q-details]
version = "1.13.3"
hash = "0c82fc60be46f6a51eff3da52861611e534e39a6"
date = "2025-08-11T21:20:15.725305Z (9d ago)"

[system-info]
os = "macOS 15.5.0 (24F74)"
chip = "Apple M1"
total-cores = 8
memory = "16.00 GB"

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

[env-vars]
DISPLAY = "/private/tmp/com.apple.launchd.HHcUHSKAaf/org.xquartz:0"
PATH = "/Users/USER/.local/bin:/Users/USER/google-cloud-sdk/bin:/Users/USER/.local/state/fnm_multishells/65016_1755495771523/bin:/Users/USER/.local/state/fnm_multishells/65005_1755495771460/bin:FNM_PATH:/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/TeX/texbin:/usr/local/go/bin:/Users/USER/.local/bin:/Users/USER/Library/pnpm:/Users/USER/google-cloud-sdk/bin:/Users/USER/.local/state/fnm_multishells/35753_1755490955870/bin:/Users/USER/.local/state/fnm_multishells/35724_1755490955786/bin:FNM_PATH:/Users/USER/miniforge3/condabin:/opt/homebrew//bin:/usr/local/go/bin:/opt/homebrew//bin:/Users/USER/.local/bin"
QTERM_SESSION_ID = "f52dadbacd4946e1b32f0d71dbb6f492"
Q_SET_PARENT_CHECK = "1"
Q_TERM = "1.13.3"
SHELL = "/bin/zsh"
TERM = "xterm-256color"
ZDOTDIR = "/Users/USER"
__CFBundleIdentifier = "com.todesktop.230313mzl4w4u92"
```