Refine users table and reconnect handling

server/lib/traffic.ts

@@ -14,6 +14,7 @@ export interface ObservedTraffic {
   activeUsers: number;
   daily: DailyTrafficBucket[];
   userBytesByName: Map<string, number>;
+  lastSeenByName: Map<string, string | null>;
   recentUsers: Set<string>;
 }
 
@@ -34,6 +35,7 @@ export async function readObservedTraffic(
   const history = buildHistoryDays(historyStart, HISTORY_DAYS);
   const dailyTotals = new Map(history.map((entry) => [entry.key, 0]));
   const userBytesByName = new Map(users.map((user) => [user.username, 0]));
+  const lastSeenByName = new Map<string, string | null>(users.map((user) => [user.username, null]));
   const recentUsers = new Set<string>();
   let liveConnections = 0;
 
@@ -47,6 +49,13 @@ export async function readObservedTraffic(
       userBytesByName.set(record.username, (userBytesByName.get(record.username) ?? 0) + record.bytes);
     }
 
+    if (lastSeenByName.has(record.username)) {
+      const currentLastSeen = lastSeenByName.get(record.username);
+      if (!currentLastSeen || record.timestamp.toISOString() > currentLastSeen) {
+        lastSeenByName.set(record.username, record.timestamp.toISOString());
+      }
+    }
+
     const ageMs = now.getTime() - record.timestamp.getTime();
     if (ageMs >= 0 && ageMs <= RECENT_WINDOW_MS) {
       recentUsers.add(record.username);
@@ -76,6 +85,7 @@ export async function readObservedTraffic(
     activeUsers,
     daily,
     userBytesByName,
+    lastSeenByName,
     recentUsers,
   };
 }