[codex] add disabled settings PCB badge

[EKKOLearnAI]

Summary

• Add a reusable settings PCB badge component with the selected PCB style and alternative draft styles preserved in comments.
• Keep the badge disabled for now by commenting out the settings button references, so no badge/logo is rendered in the sidebar.
• Add the required chat-chain change fragment for the touched chat sidebar files.
• Include the generated OpenAPI update for the active TTS settings endpoint.

Validation

• npm run build
• npm run harness:check
• git diff --check