LAYER 1: LOCATION
When a member taps Check In, we ping their device GPS against the event coordinates. Outside a 100m radius? Tap rejected. We do this on-device, no continuous tracking, no creepy stuff. One ping, one decision.
LAYER 2: QR
Hosts get a one-time QR code per event window. Members scan it in person. The code rotates every 60 seconds so screenshots posted in the group chat won't work. If you weren't in the room, you can't scan the room.
LAYER 3: PHOTO
For events where QR is awkward (a beach, a hike, a swap), members upload a quick photo of the gathering. Hosts confirm. We don't want surveillance — we want a fingerprint that says someone was there.
Three layers. Zero ghosts. Every coin earned the hard way.
