UX Issue: /extra-usage promotion requires Desktop activation but appears in CLI

Problem Description

Claude Code displays a promotional message encouraging users to activate "$50 free extra usage" using the command /extra-usage:

Opus 4.6 is here · $50 free extra usage · Try fast mode or use it when you hit a limit
/extra-usage to enable

However, when users type /extra-usage in Claude Code CLI, they receive:

Unknown skill: extra-usage

Root cause: The promotional credit must be claimed in Claude Desktop application, not Claude Code CLI, but no guidance is provided to redirect users.

Steps to Reproduce

1. See promotional banner in Claude Code CLI
2. Type /extra-usage as instructed
3. Receive "Unknown skill: extra-usage" error
4. No further guidance provided

Expected Behavior

One of the following:

• /extra-usage command should display a message: "Open Claude Desktop to claim this promotion"
• Promotional message should specify: "Open Claude Desktop to claim"
• Allow claiming directly from CLI with web authentication flow

Actual Behavior

• Claude Code interprets /extra-usage as a skill name (due to / prefix triggering skill detection)
• No built-in command handling for /extra-usage
• No redirect guidance to Claude Desktop
• User left confused about how to claim promotion

Impact

• Poor user experience for CLI-first users
• Promotional feature goes unused due to unclear activation path
• Increases support burden

Environment

• Claude Code version: 2.1.37
• Platform: macOS (Darwin 25.2.0)

Suggested Fixes

1. Short-term: Add special handling for /extra-usage to show Desktop redirect message
2. Medium-term: Allow web-based claiming that works from CLI
3. Long-term: Unify promotional activation across all Claude interfaces