Guest Passes Upsell Banner

What: Promotional UI elements that inform eligible users about their 3 available guest passes for sharing Claude Code.

How it appears:

• Banner in header showing [✻] [✻] [✻] · 3 guest passes at /passes
• Sidebar feed card with styled guest pass promotion
• Only shown to eligible users who haven't visited /passes yet
• Stops showing after 3 impressions

Details:

• Uses existing /passes command infrastructure (the command existed in v2.0.56)
• Tracks passesUpsellSeenCount and hasVisitedPasses in persistent state
• Analytics events: tengu_guest_passes_upsell_shown, tengu_guest_passes_visited
• Evidence: New functions E69() at line 474712, O69() at line 474842, HT3() at line 474824, CI1() at line 474832