ISW Territory events — changes in control/advance status.

v3 (post-2026-04-26): events are per-subscription. Each event includes subscription context (label, check_type, geometry-derived coverage/distance, market_slug_pattern). Backward-compat fields (city/event_type/severity/details/timestamp) are preserved.

Query params: hours — lookback window (default 24, max 720) city — filter by city name subscription_id — filter by specific subscription check_type — filter by 'single' / 'enter' / 'entirety' min_severity — return only events at or above this severity (SAFE / LOW / MEDIUM / HIGH / CRITICAL) limit — max events (default 50, max 200)