v1.1 - Dogfooding workflow and README refresh

What's new

• Dogfooding workflow - CodeCritic now reviews its own pull requests (.github/workflows/codecritic.yml). Every PR to this repo gets an AI review comment, the same flow users get.
• README refresh - clearer Quick Start, permissions table, troubleshooting, AI disclosure, and a data & privacy section.
• Branding - wordmark header and Marketplace/website/docs badges.

The action itself (action.yml, scripts/) is unchanged since v1 - pin @v1 or @v1.1, both give the same behavior.

Install: GitHub Marketplace
Setup guide: https://code-critic.com/github-action-code-review

Full changelog: v1...v1.1