Feature Request: Improve context file management with fuzzy find and CLI commands

### 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

Linux 5.10.234-206.921.amzn2int.x86_64 - Amazon Linux 2

### Expected behaviour

Amazon Q CLI should support:
1. Fuzzy find functionality to insert filenames inline (similar to Claippy's ctrl-u feature)
2. Command-line options to add/remove context files (e.g., `q context add --project myproject myfile`)

### Actual behaviour

Currently, Amazon Q CLI lacks the fuzzy find functionality that Claippy supports with `fzf`/`skim` integration. It also doesn't support managing context files directly from the command line, making it difficult to incorporate context changes into existing shell workflows.

```
[chat-transcript]
> /help

> !ls

> !'ls'

> !'ls .'

> !fzf

> !fzf

> !fzf

> /context !fzf

> /issue help

I'd be happy to help you report an issue or make a feature request for Amazon Q. Let me guide you through the process.

You can use the built-in `report_issue` tool to open a pre-filled GitHub issue template. This will include your conversation transcript and relevant context to help the team understand your feedback.

Would you like to:
1. Report a bug you've encountered
2. Request a new feature
3. Provide general feedback

Please let me know which option you prefer, and provide some details about the issue or feature request you'd like to submit. This will help me create an appropriate title and pre-fill the GitHub issue template with relevant information.
[Tool uses: none]

> I would like less friction adding context files. Two features that claippy supports that Q CLI does not are: >
- fuzzy find to insert a filename inline within a command (i.e., the file should be inserted into the prompt). `fzf` provides the functionality in bash, and the rust crate `skim` also implements it. Possibly a more general way to do this would be to support e.g. `/context add !!{fzf}` or something. In claippy ctrl-u just opens a skim dialog.>
- somewhat similarly, supporrt adding/removing context from the command line, e.g. `q context add --project myproject myfile`, so that context changes can be incorporated into existing shell workflows

Thank you for sharing these feature requests for improving context file management in Amazon Q CLI. Let me submit this feedback using the report_issue tool.
[Tool uses: report_issue]
```

### Steps to reproduce

N/A - This is a feature request for new functionality

### Environment

```yaml
(redacted amazon internal info)
```

まず既存の `q context` コマンドと `/context` の処理を確認し、次に CLI が現在どのようにファイル名を受け付け、コンテキストを管理しているかを比較します。ユーザーがインラインでファイル名を fuzzy-select し、shell で扱いやすい `q context` コマンドによってコンテキストファイルを追加または削除でき、両方の機能パスについて動作が定義されれば、依頼された作業は完了です。

索引モデルが issue の本文から書いたものです。