Feature request: add `tea` subcommand for Gitea CLI

Summary

RTK currently has a gh subcommand that filters and compacts GitHub CLI output. I'd like the same treatment for tea — the official Gitea CLI — so that rtk tea <cmd> produces token-optimized output in the same way.

Motivation

I use Gitea for self-hosted repos alongside GitHub. The tea CLI produces verbose, human-formatted output (issue lists, PR details, repo info) that is similarly token-heavy to raw gh output. Having an rtk tea subcommand would extend the same 60-90% savings to Gitea workflows.

Common commands that would benefit

• tea issue list — tabular output with full descriptions
• tea pr list / tea pr show — PR metadata and diffs
• tea repo info — repo statistics
• tea release list — release listings

Tea version

tea 0.14.0  golang: 1.26.2  built with: Homebrew

Reference

The gh subcommand seems like a natural template for this. Happy to help test or contribute if there's guidance on adding a new subcommand.