fix(api): active session count excludes killed/completed/crashed (#3334) (#3396)

/v1/sessions/stats now filters out killed, completed, and crashed
sessions from the 'active' count. The 'byStatus' breakdown still
includes all statuses for full visibility.

Fixes: #3334

Author: OneStepAt4time

src/routes/sessions.ts

@@ -263,8 +263,10 @@ export function registerSessionRoutes(app: FastifyInstance, ctx: RouteContext):
       byStatus[s.status] = (byStatus[s.status] ?? 0) + 1;
     }
     const global = metrics.getGlobalMetrics(all.length);
+    // #3334: active should only count live sessions, not killed/completed/crashed
+    const activeCount = all.filter(s => s.status !== "killed" && s.status !== "completed" && s.status !== "crashed").length;
     return {
-      active: all.length,
+      active: activeCount,
       byStatus,
       totalCreated: global.sessions.total_created,
       totalCompleted: global.sessions.completed,