feat: add alerting system with configurable rules and UI (MON-02, MON-03)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

core/archipelago/src/server.rs

@@ -78,7 +78,7 @@ impl Server {
 
         // Create metrics store and spawn background collector
         let metrics_store = Arc::new(MetricsStore::new());
-        crate::monitoring::spawn_metrics_collector(metrics_store.clone());
+        crate::monitoring::spawn_metrics_collector(metrics_store.clone(), Some(state_manager.clone()));
 
         let api_handler = Arc::new(
             ApiHandler::new(config.clone(), state_manager.clone(), metrics_store).await?,