Add version numbers next to key integrations that are often not up-to-date with the GitHub version

[hippietrail]

Issues

N/A

Description

Some integrations take some time to update to the new Harper version once it's published on GitHub.

This PR adds the current version numbers for the Firefox, JavaScript/npm, VS Code, and Rust (Cargo) integrations.

I'm not really satisfied with the size and placement of the version text and font. I'm not a webdev guy.

I feel that the current GitHub release version number should be somewhere too so we can see how far behind any integration is. But I'm not sure where it would fit. I know to do the code as the latest version number is available at https://writewithharper.com/latestversion it would be trivial to add using the same methods the PR already employs.

I tried to add the Chrome one, but couldn't find any JSON feed or API and CORS prevents scraping the HTML. Google AI told me Svelte can do some kind of microserver thingy to fetch, but that sounded like going too far.

The LSP-based ones don't have version lag. Obsidian uses our repo. Did I miss any?

Demo

How Has This Been Tested?

Manually

AI Disclosure

• I am a human and didn't use any AI.
• I used LLM features of my editor, but not an agent.
• I used an AI agent interactively.
• I am an agent or I got an agent to do the work autonomously.

I got Google to iterate on the code too, which is between an in-editor AI and an agent I think.

Checklist

• I have performed a self-review of my own code
• I have added tests to cover my changes
• I have considered splitting this into smaller pull requests.