#36 · Geofence triggers — fire webhook when a marker enters/exits a region

Context

TAK already tracks markers (positions). Adding geofences (named polygons stored in D1) and emitting webhooks on enter/exit makes the service useful for transport runs, perimeter alerts, training events.

Acceptance criteria

• [ ] POST /api/geofences creates a polygon (name, coords, owner)
• [ ] Marker updates check geofence membership; transitions emit webhook to subscriber URL
• [ ] Webhook payload: { marker_id, geofence_id, transition: 'enter'|'exit', timestamp }
• [ ] Subscribers stored per-geofence in D1; signed with shared secret

Technical hints

• Use Turf.js (or hand-rolled point-in-polygon) — Workers-compatible
• Read apps/tak-service/docs/ldap-setup-progress.md for current state — auth is the prerequisite

--- *Submit a merge request that says Closes #<this issue iid> in the description. On merge to main, the GitLab webhook will auto-award your bounty + the standard merge_pr (40 pts) to your scoreboard account. Email on commit must match your Authentik email.*