feart: Enhances clipboard copying with MIME type selection

[twofingerrightclick]

Introduces a new component to allow copying text content to the clipboard with various MIME types (e.g., plain text, HTML, Markdown). Useful when you want to copy a type as another type. Defaults to plain/text.

Utilizes the ClipboardItem API for rich data transfers, falling back to writeText for basic plain text copy if advanced features are unavailable. The UI now includes a dropdown for MIME type selection.

Updates class attributes to className for React consistency.

[twofingerrightclick]

@danburzo This tool was a top hit on google or "What is on my clipboard"! I was about to build something like it because I needed to get html as plain text. Then I needed to get the plain text as html, so I added that in a way that I thought seemed reasonable enough. I often need to copy plain text as svg as well so added that and a few others for experimentation.

Thanks for building this!

[danburzo]

Thanks for this, @twofingerrightclick, it’s a great addition! I haven’t experimented lately with writing custom MIME types to the clipboard, but IIRC there are some things that complicate this: https://developer.chrome.com/blog/web-custom-formats-for-the-async-clipboard-api/

It warrants some testing around:

1. Whether there’s any browser that allows writing MIME types besides these three.
2. Whether text/html gets sanitized (e.g. remove <script> elements), versus web text/html which should be copied verbatim.

[twofingerrightclick]

@danburzo Thanks for pointing this out — I hadn’t fully realized at first that clipboard support is intentionally limited for certain MIME types, both for security reasons and because browser support is still inconsistent. I should have tested more.

The only formats that currently work reliably with the new copy button are plain text and HTML. Interestingly, when copying HTML, the <script> tags are preserved as part of the copied content.

I’ve adjusted it so the dropdown now only includes the two supported/reliable options.