Leave Organization returns error — "Could not leave organization."

## Steps to Reproduce 1. Log in as a regular member (not owner/host) 2. Navigate to an org public profile (e.g., "Art Group Lisbon") 3. Click "Leave Organization" 4. Confirm in the dialog 5. Click "Leave" ## Expected Membership is removed, UI updates to show "Join" button. ## Actual Toast error: **"Could not leave organization."** Network tab shows: - **DELETE** to `dev.gathrings.com/leave` - **Status: 488** - Response: `{"code": "UPSTREAM_ERROR", "message": "Could not leave organization right now."}` ## Analysis HTTP 488 is not a standard status code. The `UPSTREAM_ERROR` code suggests the BFF's DELETE call to the backend API failed or timed out. ## Environment - URL: dev.gathrings.com - Org: Art Group Lisbon (open, 89 members) - User role: Member - Date: 2026-03-08