Problem

Operators need a single destination where they can understand the readiness of Codex, Claude Code, and GitHub Copilot before opening a live session.

Scope

• Define the Toolchain Center layout, summary states, detail panels, and actions
• Cover install, detect, connect, update, and troubleshoot flows for supported providers
• Keep the surface desktop-first and easy to scan

Out of scope

• Provider adapter execution details once a session has already started
• Local model runtime configuration outside the provider toolchain scope

Implementation notes

• Treat Toolchain Center as a first-class feature, not a hidden utility dialog
• Align its information hierarchy with the current shell direction
• Make version, auth, and health state visible at a glance

Definition of Done

• The issue defines the core Toolchain Center UX and states
• Future provider-specific issues can plug into this UI contract without redesigning it

Verification

• Review the issue against the feature spec setup flow

Dependencies

• Parent epic: [Epic] Build the provider toolchain center for Codex, Claude Code, and GitHub Copilot #14
• Depends on: Build the unified settings shell for providers, policies, and storage