I think that any guides you find for Gitea + Renovate should work still for Forgejo + Renovate.

I believe the process is:

• Create Forgejo instance
• Create a user for Renovate within Forgejo
• Using the CLI on your local machine (or another tool to complete this step), create an SSH public/private key for the Renovate user
• Log into Forgejo using the Renovate user and configure the previously created SSH keys and separately generate a Forgejo token
• Create a Renovate instance with settings for at least RENOVATE_GIT_PRIVATE_KEY (SSH private key value), RENOVATE_TOKEN (Forgejo token value), RENOVATE_PLATFORM (gitea), RENOVATE_ENDPOINT (Forgejo API base URL), and any other Renovate settings that you may find helpful/necessary to configure (eg: GITHUB_COM_TOKEN, RENOVATE_AUTODISCOVER, etc.)
• Depending on how you want things to work, you may need to give the Renovate Forgejo user access to individual repos

uv

It is made by the Astral team, who made ruff and are working on a static type checker. They’re making great Python tooling and uv is no exception.