Experiment selection moves up on the screen

### 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 15.6.1 (24G90)

### Expected behaviour

When I use /experiment I expect to see a list with available experiments at the location of the current prompt. When I press the up and down arrows all items stay on the same line but the marked item (shown by a ❯ and a different colour) changes.

### Actual behaviour

When I press an arrow key the list with options moves up one line in the terminal window leaving blank lines behind until first experiment is on the first line of the screen.

Also tried this in a bash session and it doesn't happen in that case, same with a `zsh --no-rcs` session. So this might be related to Oh my Zsh/Powerleven10k

Using the same selection mechanism in `/model` doesn't show the same behaviour. Is this related to https://github.com/aws/amazon-q-developer-cli/pull/2726 ?

### Steps to reproduce

Start `q chat`
Enter `/experiment`
Use your up and down keys

### Environment

```yaml

[q-details]
version = "1.15.0"
hash = "a8a0426eaff32ac9b1599ca1b1f1881ffd16054d"
date = "2025-09-02T17:15:25.464923Z (14h ago)"

[system-info]
os = "macOS 15.6.1 (24G90)"
chip = "Apple M2 Max"
total-cores = 12
memory = "64.00 GB"

[environment]
cwd = "/Users/USER/k8s-infrastructure"
cli-path = "/Users/USER/k8s-infrastructure"
install-method = "brew"

[env-vars]
PATH = "/Users/USER/.local/bin:/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:/Applications/VMware Fusion.app/Contents/Public:/Applications/iTerm.app/Contents/Resources/utilities:/Users/USER/.krew/bin:/Applications/PhpStorm.app/Contents/MacOS:~.local/bin"
SHELL = "/bin/zsh"
TERM = "xterm-256color"
__CFBundleIdentifier = "com.googlecode.iterm2"
```

Beginne damit, das Problem mit q chat unter macOS zu reproduzieren, und vergleiche anschließend die Auswahl bei /experiment mit /model in den gemeldeten zsh-, bash- und zsh --no-rcs-Sitzungen. Verfolge das Auswahlverhalten im Terminal und den Unterschied im Zusammenhang mit Oh My Zsh oder Powerlevel10k; fertig ist es, wenn die Navigation mit den Pfeiltasten die Optionen in einer Zeile hält, ohne Leerzeilen zu hinterlassen.

Vom Indexierungsmodell aus dem Issue-Text verfasst.