Phase 3 | Priority: P0 | Status: Not Started

Objective

Add feature flag referral_program_enabled to control rollout and allow instant disable if issues arise.

Acceptance Criteria

• Flag: referral_program_enabled (boolean, default: false)
• When disabled: Invite Friends nav link hidden; /settings/invite-friends returns 404
• When disabled: /join/[CODE] still works (don't break existing shared links)
• Flag toggleable via admin panel without deploy
• Tested: flag on/off behavior verified in staging

Dependencies

Depends on: Invite Friends page. Blocks: launch.