Phase 3A: Site runtime foundation — Akka cluster, SQLite persistence, Deployment Manager singleton, Instance Actor

- WP-1: Site cluster config (keep-oldest SBR, down-if-alone, 2s/10s failure detection)
- WP-2: Site-role host bootstrap (no Kestrel, SQLite paths)
- WP-3: SiteStorageService with deployed_configurations + static_attribute_overrides tables
- WP-4: DeploymentManagerActor as cluster singleton with staggered Instance Actor creation,
  OneForOneStrategy/Resume supervision, deploy/disable/enable/delete lifecycle
- WP-5: InstanceActor with attribute state, GetAttribute/SetAttribute, SQLite override persistence
- WP-6: CoordinatedShutdown verified for graceful singleton handover
- WP-7: Dual-node recovery (both seed nodes, min-nr-of-members=1)
- WP-8: 31 tests (storage CRUD, actor lifecycle, supervision, negative checks)
389 total tests pass, zero warnings.

src/ScadaLink.Host/Program.cs

@@ -136,8 +136,9 @@ try
             services.AddExternalSystemGateway();
             services.AddNotificationService();
 
-            // Site-only components
-            services.AddSiteRuntime();
+            // Site-only components — AddSiteRuntime registers SiteStorageService with SQLite path
+            var siteDbPath = context.Configuration["ScadaLink:Database:SiteDbPath"] ?? "site.db";
+            services.AddSiteRuntime($"Data Source={siteDbPath}");
             services.AddDataConnectionLayer();
             services.AddStoreAndForward();
             services.AddSiteEventLogging();
@@ -148,6 +149,7 @@ try
 
             // Options binding
             BindSharedOptions(services, context.Configuration);
+            services.Configure<SiteRuntimeOptions>(context.Configuration.GetSection("ScadaLink:SiteRuntime"));
             services.Configure<DataConnectionOptions>(context.Configuration.GetSection("ScadaLink:DataConnection"));
             services.Configure<StoreAndForwardOptions>(context.Configuration.GetSection("ScadaLink:StoreAndForward"));
             services.Configure<SiteEventLogOptions>(context.Configuration.GetSection("ScadaLink:SiteEventLog"));