Preserve fleet match timing across empty telemetry

src/lib/server/fleet/status-updates.ts

@@ -20,15 +20,13 @@ export function successfulStatusFields(
     };
 }
 
-/** Occupancy timers and match clearing follow the same source as the UI. */
+/** Occupancy follows the UI's source; only gameplay evidence changes match timing. */
 export function activityFields(current: ServerRow, status: ServerObservation): Partial<ServerRow> {
     if (status.health !== 'online' || status.last_players === null) return {};
     return status.last_players > 0
         ? { active_since: current.active_since ?? status.last_seen_at, inactive_since: null }
         : {
               active_since: null,
-              inactive_since: current.inactive_since ?? status.last_seen_at,
-              game_started_at: null,
-              game_ended_at: null
+              inactive_since: current.inactive_since ?? status.last_seen_at
           };
 }