support for multiple repository in gitea integration

Problem Statement

I use Linear at work, and the multiple repository Github integration is really nice and something I miss with the Gitea integration in Kaneo.

Proposed Solution

Add support for multiple repository integration with Gitea, through multiple webhooks, one per repository ?

Alternative Solutions

I guess the current alternative is to create one project per repository, but not having the issues from the frontend and backend together is a bit cumbersome.

Relevant Context

Nothing

Does this feature align with Kaneo's focus on simplicity?

I guess so 🤔
From my bird's view, it does not appear to be too complex to add another button next to the update one, in the Gitea integration interface.

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Originally requested by @Betelgeuse1 on 2026-05-22. Original GitHub request #1282.