Adds point_alarm.py (flattening, secret masking, SQLite upsert store, paged fetch with 403 fallback, CSV/TXT export, shared filter loader), nowcast-point-page.py CLI and unit tests. Register will read the shared filter from nowcast-point-alarm-filter.json instead of repeating it in the CSV.
Move webhook config loading, UUID and warning helpers and the atomic semicolon CSV writer out of geo_alarm so the upcoming point alarm clients can reuse them. Behavior is unchanged and the existing geo tests still pass.
mozdemir