fix(README): Add claude code since it is now supported

[Mrid22]

What Changed

In the README, where it has the notice that you need Codex installed and authorized for T3 Code to work, i mentioned that you can instead use Claude code since it is now supported

Why

So that people with a Claude Code subscription are aware that it's an option

Checklist

• This PR is small and focused
• I explained what changed and why
• I included before/after screenshots for any UI changes
• I included a video for animation/interaction changes

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Note

Low Risk
Documentation-only change clarifying an additional supported CLI; no runtime or security behavior is modified.

Overview
Updates README.md How to use warning to state that either Codex CLI or Claude Code must be installed and authorized to use T3 Code.

^{Written by Cursor Bugbot for commit 0102acf. This will update automatically on new commits. Configure here.}

Note

Add Claude Code as a supported CLI option in the README

Updates the prerequisite note in README.md to list Claude Code alongside Codex CLI, with a link to Claude Code's documentation.

^{Macroscope summarized 0102acf.}