[FEATURE] Add Opus 4.6 1M to co-work

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

I want to be able to auto-select one million contacts window when using co-work in Claude desktop.

Proposed Solution

Opus 4.6, 1 million context window to default models, and Claude co-work.

Alternative Solutions

_No response_

Priority

Critical - Blocking my work

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

_No response_