Feature request: selectively clear context / chat-history

### 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

I'd like to "selectively" clear my session history, e.g. I want to delete only the last prompt-response pair as they pollute the context. Where do we send this kind of feature requests?

### Actual behaviour

`/clear` clears entire context.

### Steps to reproduce

_No response_

### Environment

```yaml

[q-details]
version = "1.19.3"
hash = "84b82da54996570ac369ec69911e29b524099761"
date = "2025-10-29T21:11:53.813462Z (8d ago)"
variant = "full"

[system-info]
os = "macOS 15.7.1 (24G231)"
chip = "Apple M1 Pro"
total-cores = 10
memory = "32.00 GB"

[environment]
cwd = "/Users/USER/ws/qc"
cli-path = "/Users/USER/ws/qc"
os = "Mac"
shell-path = "/Users/USER/.toolbox/tools/toolbox/1.1.2259.0/toolbox-exec"
shell-version = "5.9"
terminal = "macOS"
install-method = "brew"

[env-vars]
PATH = "/Users/USER/.local/bin:/Users/USER/Downloads/apache-maven-3.9.9/bin:/opt/homebrew/opt/node@12/bin:/Users/USER/.toolbox/bin:/opt/homebrew/opt/ruby/bin:/Users/USER/ws/apache-maven-3.9.6/bin:/Users/USER/anaconda3/bin:/Users/USER/anaconda3/condabin:/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:/Users/USER/Library/Application Support/JetBrains/Toolbox/scripts"
SHELL = "/bin/zsh"
TERM = "xterm-256color"
__CFBundleIdentifier = "com.apple.Terminal"
```

Beginne am Einstiegspunkt des Befehls /clear und verfolge, wie Sitzungsverlauf und Kontext dargestellt werden. Lege fest, wie ein Benutzer das letzte Prompt-Antwort-Paar oder einen anderen Bereich auswählt, füge anschließend Testabdeckung für die Beibehaltung des verbleibenden Kontexts hinzu und überprüfe, dass das bestehende Verhalten zum vollständigen Löschen weiterhin funktioniert.

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