feat: Phase 2 data aggregation pipeline (Strike 4A)

Backend:
- Stats ingestion consumer subscribing to corrosion.*.stats NATS subject
- Hourly aggregation scheduler (runs :05 past every hour)
- Daily cleanup job (03:00 UTC) with 7-day raw / 90-day hourly retention
- Analytics API (summary, timeseries, CSV export)
- Complete stats DB queries with aggregation and cleanup

Frontend:
- Analytics dashboard with ECharts integration
- Player count and server performance charts
- Time range selector (24h/7d/30d)
- CSV export functionality
- Real-time data loading

Infrastructure:
- Exposed NatsBridge.jetstream for consumer access
- Background service initialization in main.rs

Data flow: Plugin → NATS → Consumer → DB → Aggregation → API → Charts

Unblocks Strike 4B (dashboards) and 4C (alerting).

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

backend/src/main.rs

@@ -65,6 +65,43 @@ async fn main() -> anyhow::Result<()> {
     // Bootstrap: create admin user + license on first run
     bootstrap_admin(&db).await;
 
+    // Initialize background services if NATS is available
+    if let Some(ref nats_client) = nats {
+        let nats_bridge = Arc::new(services::nats_bridge::NatsBridge::new(nats_client.clone()));
+
+        // Start stats consumer
+        let stats_consumer = services::stats_consumer::StatsConsumerService::new(
+            db.clone(),
+            nats_bridge.clone(),
+        );
+        if let Err(e) = stats_consumer.start().await {
+            tracing::error!("Failed to start stats consumer: {}", e);
+        }
+
+        // Start scheduler service
+        let scheduler = services::scheduler::SchedulerService::new(
+            db.clone(),
+            nats_bridge.clone(),
+        )
+        .await?;
+
+        // Register stats jobs
+        if let Err(e) = scheduler.register_stats_aggregation().await {
+            tracing::error!("Failed to register stats aggregation job: {}", e);
+        }
+        if let Err(e) = scheduler.register_stats_cleanup().await {
+            tracing::error!("Failed to register stats cleanup job: {}", e);
+        }
+
+        if let Err(e) = scheduler.start().await {
+            tracing::error!("Failed to start scheduler: {}", e);
+        } else {
+            tracing::info!("Scheduler service started");
+        }
+    } else {
+        tracing::warn!("Skipping background services (NATS not available)");
+    }
+
     let state = Arc::new(AppState { db, nats, config });
 
     // CORS — permissive in dev, locked down in production
@@ -91,6 +128,7 @@ async fn main() -> anyhow::Result<()> {
         .nest("/api/early-access", api::early_access::router())
         .nest("/api/admin", api::admin::router())
         .nest("/api/ws", api::ws::router())
+        .nest("/api/analytics", api::analytics::router())
         .layer(cors)
         .layer(TraceLayer::new_for_http())
         .with_state(state);