feat: (web) add help doc to explain PAT handling

[cyclotruc]

We need a popup to explain how we handle the PAT:
Never stored
Only used to clone repo
No caching in frontend client storage (yet)

[geoffreylgv]

As someone who is passionate about developer experience and open-source contribution, I believe that improving clarity around authentication mechanisms such as Personal Access Tokens (PATs) is crucial. Clear documentation and helpful UI messages are essential for building user trust and ensuring transparency, particularly when handling sensitive data such as tokens. I have worked on several front-end and documentation-focused issues across open-source projects such as OpenSauced and Oppia.

Recommended by OnlyDust for outstanding experience and quality contributions.

[cyclotruc]

Hi @geoffreylgv
Do you want to tackle this one? Let me know and I'll then assign to you
Thank you!

[RautAtharv07]

Hello,
I have experience working with HTML, Tailwind CSS, and Jinja templating, and I’ve already implemented the popup to explain PAT usage and ensured it's styled and aligned with the existing UI
I just need a quick clarification on alignment and behavior details — the implementation is mostly done.

Please assign me this issue so I can finalize the PR.

Recommended by OnlyDust for high-quality and dependable contributions.

[filipchristiansen]

Hey @geoffreylgv and @RautAtharv07! Feel free to make a PR :)

[Kdmeenaa]

i want to handle .

[RautAtharv07]

Hi @filipchristiansen and @cyclotruc I've completed the popup implementation and attached the screenshots.
Please have a look and let me know if anything needs to be changed or improved.

[filipchristiansen]

Thank you for your efforts @RautAtharv07! We felt this to be too verbose and went for a more subtle approach #348.

[RautAtharv07]

Thank you @filipchristiansen your feedback and for reviewing my contribution!
If there's anything else I can help with I'd love to contribute.