Tasks
[x] Add and run failing viewport and movement regressions.
[x] Share geographic predicates and validate/apply Explore bounds.
[x] Connect throttled live map movement to list queries without camera resets.
[x] Add IP-based initialization with failure/interaction safeguards.
[x] Add safe marker hover/focus popups and lifecycle tests.
[x] Run quality gates, regenerate API types, and update frontend/API/checklist documentation.
[x] Reproduce continuous-motion filtering failure, fix event delivery and throttling, verify live DOM updates, and update the PR.