feat(telemetry): rollups, alerts, scheduler, health checks, admin server fns

- pure rollup accumulators with tests; daily upserts keyed date/metric/dim
- alert checks with db-backed cooldown and push to admin players
- in-process scheduler started from health probes
- health endpoint checks pb + supertokens, stale-while-revalidate, always 200
- sse connection counter moved to emitter
- telemetry feature server fns: events/errors/groups/rollups/alerts/status

src/app/routes/api/events.$.ts

@@ -1,9 +1,14 @@
 import { createFileRoute } from "@tanstack/react-router";
-import { serverEvents, EVENT_TYPES, type ServerEvent } from "@/lib/events/emitter";
+import {
+  serverEvents,
+  EVENT_TYPES,
+  incrementConnections,
+  decrementConnections,
+  type ServerEvent,
+} from "@/lib/events/emitter";
 import { logger } from "@/lib/logger";
 import { superTokensRequestMiddleware } from "@/utils/supertokens";
 
-let activeConnections = 0;
 const encoder = new TextEncoder();
 
 export const Route = createFileRoute("/api/events/$")({
@@ -11,9 +16,9 @@ export const Route = createFileRoute("/api/events/$")({
     middleware: [superTokensRequestMiddleware],
     handlers: {
       GET: ({ request }) => {
-        activeConnections++;
+        const active = incrementConnections();
         const connectionId = `conn_${Date.now()}_${Math.random().toString(36).substring(2, 11)}`;
-        logger.info(`ServerEvents | New connection ${connectionId}. Active: ${activeConnections}`);
+        logger.info(`ServerEvents | New connection ${connectionId}. Active: ${active}`);
 
         let cleanedUp = false;
         let cleanup = () => {};
@@ -41,12 +46,12 @@ export const Route = createFileRoute("/api/events/$")({
             cleanup = () => {
               if (cleanedUp) return;
               cleanedUp = true;
-              activeConnections--;
+              const remaining = decrementConnections();
               for (const type of EVENT_TYPES) {
                 serverEvents.off(type, handleEvent);
               }
               clearInterval(pingInterval);
-              logger.info(`ServerEvents | Connection ${connectionId} cleanup completed. Active: ${activeConnections}`);
+              logger.info(`ServerEvents | Connection ${connectionId} cleanup completed. Active: ${remaining}`);
             };
 
             request.signal?.addEventListener("abort", cleanup);