Feature request: Add /prompts create subcommand to create prompt from within CLI

### 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 15.4.1 (24E263)

### Expected behaviour

Add a new subcommand `/prompts create` that would allow users to create new prompts directly from within the Amazon Q CLI interface, without having to leave the CLI environment.

Currently, only /prompts list and /prompts get command exist and there is no easy way to add reusable prompts other than probably through MCP. Having a /prompts create command will allow users to create reusable prompts from within CLI. It should be possible to either write the prompt context as in the command itself or create from a file stored somewhere.

I asked Q for creating prompts and it suggested these commands, which looks reasonable and intuitive.

```
q prompts create --name "my-prompt-name" --content-file /path/to/your/prompt.md
q prompts create --name "my-prompt-name" --content "Your prompt content here"
```

### Actual behaviour

```
[chat-transcript]
> /help

> /issue

I'd be happy to help you report an issue or make a feature request. To do this, I can use the `report_issue` function to open a pre-filled GitHub issue template.

Could you please provide:
1. A title for your issue or feature request
2. What behavior you're experiencing (if it's an issue)
3. What behavior you expected (if applicable)
4. Any steps to reproduce the issue (if relevant)

Once you provide these details, I can help you submit the report.
[Tool uses: none]

> Feature request: Add /prompts create subcommand to create prompt from within cli

I understand you'd like to make a feature request for adding a `/prompts create` subcommand to create prompts from within the CLI. Let me help you submit this feature request.
[Tool uses: report_issue]
```

The /prompts create doesn't exist though somehow Q CLI think it exist. I think it should exist.

### Steps to reproduce

_No response_

### Environment

```yaml

[q-details]
version = "1.8.0"
hash = "dd7442517f2f878fde45c744863412868eee7574"
date = "2025-04-23T18:52:24.776083Z (20h ago)"
variant = "full"

[system-info]
os = "macOS 15.4.1 (24E263)"
chip = "Apple M3 Pro"
total-cores = 12
memory = "36.00 GB"

[environment]
cwd = "/Volumes/workplace/q-power-user/src/AmazonBuilderGenAIPowerUsersQContext"
cli-path = "/Volumes/workplace/q-power-user/src/AmazonBuilderGenAIPowerUsersQContext"
os = "Mac"
shell-path = "/Users/USER/.toolbox/tools/toolbox/1.1.1762.0/toolbox-exec"
shell-version = "5.9"
terminal = "Ghostty"
install-method = "toolbox"

[env-vars]
DISPLAY = "/private/tmp/com.apple.launchd.avSV9FuCRJ/org.xquartz:0"
PATH = "/Users/USER/.local/share/mise/installs/node/22.12.0/bin:/Users/USER/.local/share/mise/installs/python/3.12.3/bin:/Users/USER/.local/share/mise/installs/python/3.11.9/bin:/Users/USER/.local/share/mise/installs/python/3.10.14/bin:/Users/USER/.local/share/mise/installs/python/3.9.19/bin:/Users/USER/.local/share/mise/installs/python/3.8.19/bin:/Users/USER/.local/share/mise/installs/usage/0.1.18/bin:/opt/homebrew/bin:/opt/homebrew/sbin:/Users/USER/bin:/Users/USER/.toolbox/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/X11/bin:/Applications/Ghostty.app/Contents/MacOS:/Applications/Visual Studio Code.app/Contents/Resources/app/bin:/Users/USER/Library/Application Support/JetBrains/Toolbox/scripts:/Users/USER/.antigen/bundles/robbyrussell/oh-my-zsh/lib:/Users/USER/.antigen/bundles/robbyrussell/oh-my-zsh/plugins/git:/Users/USER/.antigen/bundles/robbyrussell/oh-my-zsh/plugins/fzf:/Users/USER/.antigen/bundles/zsh-users/zsh-completions:/Users/USER/.antigen/bundles/zsh-users/zsh-autosuggestions:/Users/USER/.antigen/bundles/zsh-users/zsh-syntax-highlighting:/Users/USER/.antigen/bundles/romkatv/powerlevel10k:/opt/homebrew/opt/fzf/bin"
SHELL = "/bin/zsh"
TERM = "xterm-ghostty"
__CFBundleIdentifier = "com.mitchellh.ghostty"

[chat-settings]
interactive=true

[chat-trusted_tools]

[chat-failed_request_ids]
none

[chat-context]
current_profile=default
profiles=
default

global_context=none

profile_context=none

files=none
```