Phase 3B: Site I/O & Observability — Communication, DCL, Script/Alarm actors, Health, Event Logging

Communication Layer (WP-1–5):
- 8 message patterns with correlation IDs, per-pattern timeouts
- Central/Site communication actors, transport heartbeat config
- Connection failure handling (no central buffering, debug streams killed)

Data Connection Layer (WP-6–14, WP-34):
- Connection actor with Become/Stash lifecycle (Connecting/Connected/Reconnecting)
- OPC UA + LmxProxy adapters behind IDataConnection
- Auto-reconnect, bad quality propagation, transparent re-subscribe
- Write-back, tag path resolution with retry, health reporting
- Protocol extensibility via DataConnectionFactory

Site Runtime (WP-15–25, WP-32–33):
- ScriptActor/ScriptExecutionActor (triggers, concurrent execution, blocking I/O dispatcher)
- AlarmActor/AlarmExecutionActor (ValueMatch/RangeViolation/RateOfChange, in-memory state)
- SharedScriptLibrary (inline execution), ScriptRuntimeContext (API)
- ScriptCompilationService (Roslyn, forbidden API enforcement, execution timeout)
- Recursion limit (default 10), call direction enforcement
- SiteStreamManager (per-subscriber bounded buffers, fire-and-forget)
- Debug view backend (snapshot + stream), concurrency serialization
- Local artifact storage (4 SQLite tables)

Health Monitoring (WP-26–28):
- SiteHealthCollector (thread-safe counters, connection state)
- HealthReportSender (30s interval, monotonic sequence numbers)
- CentralHealthAggregator (offline detection 60s, online recovery)

Site Event Logging (WP-29–31):
- SiteEventLogger (SQLite, 6 event categories, ISO 8601 UTC)
- EventLogPurgeService (30-day retention, 1GB cap)
- EventLogQueryService (filters, keyword search, keyset pagination)

541 tests pass, zero warnings.

src/ScadaLink.SiteRuntime/Actors/DeploymentManagerActor.cs

@@ -1,9 +1,12 @@
 using Akka.Actor;
 using Microsoft.Extensions.Logging;
+using ScadaLink.Commons.Messages.Artifacts;
 using ScadaLink.Commons.Messages.Deployment;
 using ScadaLink.Commons.Messages.Lifecycle;
 using ScadaLink.Commons.Types.Enums;
 using ScadaLink.SiteRuntime.Persistence;
+using ScadaLink.SiteRuntime.Scripts;
+using ScadaLink.SiteRuntime.Streaming;
 
 namespace ScadaLink.SiteRuntime.Actors;
 
@@ -20,6 +23,9 @@ namespace ScadaLink.SiteRuntime.Actors;
 public class DeploymentManagerActor : ReceiveActor, IWithTimers
 {
     private readonly SiteStorageService _storage;
+    private readonly ScriptCompilationService _compilationService;
+    private readonly SharedScriptLibrary _sharedScriptLibrary;
+    private readonly SiteStreamManager? _streamManager;
     private readonly SiteRuntimeOptions _options;
     private readonly ILogger<DeploymentManagerActor> _logger;
     private readonly Dictionary<string, IActorRef> _instanceActors = new();
@@ -28,10 +34,16 @@ public class DeploymentManagerActor : ReceiveActor, IWithTimers
 
     public DeploymentManagerActor(
         SiteStorageService storage,
+        ScriptCompilationService compilationService,
+        SharedScriptLibrary sharedScriptLibrary,
+        SiteStreamManager? streamManager,
         SiteRuntimeOptions options,
         ILogger<DeploymentManagerActor> logger)
     {
         _storage = storage;
+        _compilationService = compilationService;
+        _sharedScriptLibrary = sharedScriptLibrary;
+        _streamManager = streamManager;
         _options = options;
         _logger = logger;
 
@@ -41,6 +53,9 @@ public class DeploymentManagerActor : ReceiveActor, IWithTimers
         Receive<EnableInstanceCommand>(HandleEnable);
         Receive<DeleteInstanceCommand>(HandleDelete);
 
+        // WP-33: Handle system-wide artifact deployment
+        Receive<DeployArtifactsCommand>(HandleDeployArtifacts);
+
         // Internal startup messages
         Receive<StartupConfigsLoaded>(HandleStartupConfigsLoaded);
         Receive<StartNextBatch>(HandleStartNextBatch);
@@ -317,6 +332,74 @@ public class DeploymentManagerActor : ReceiveActor, IWithTimers
         _logger.LogInformation("Instance {Instance} deleted", instanceName);
     }
 
+    /// <summary>
+    /// WP-33: Handles system-wide artifact deployment (shared scripts, external systems, etc.).
+    /// Persists artifacts to SiteStorageService and recompiles shared scripts.
+    /// </summary>
+    private void HandleDeployArtifacts(DeployArtifactsCommand command)
+    {
+        _logger.LogInformation(
+            "Deploying system artifacts, deploymentId={DeploymentId}", command.DeploymentId);
+
+        var sender = Sender;
+
+        Task.Run(async () =>
+        {
+            try
+            {
+                // WP-33: Store shared scripts and recompile
+                if (command.SharedScripts != null)
+                {
+                    foreach (var script in command.SharedScripts)
+                    {
+                        await _storage.StoreSharedScriptAsync(script.Name, script.Code,
+                            script.ParameterDefinitions, script.ReturnDefinition);
+
+                        // WP-33: Shared scripts recompiled on update
+                        _sharedScriptLibrary.CompileAndRegister(script.Name, script.Code);
+                    }
+                }
+
+                // WP-33: Store external system definitions
+                if (command.ExternalSystems != null)
+                {
+                    foreach (var es in command.ExternalSystems)
+                    {
+                        await _storage.StoreExternalSystemAsync(es.Name, es.EndpointUrl,
+                            es.AuthType, es.AuthConfiguration, es.MethodDefinitionsJson);
+                    }
+                }
+
+                // WP-33: Store database connection definitions
+                if (command.DatabaseConnections != null)
+                {
+                    foreach (var db in command.DatabaseConnections)
+                    {
+                        await _storage.StoreDatabaseConnectionAsync(db.Name, db.ConnectionString,
+                            db.MaxRetries, db.RetryDelay);
+                    }
+                }
+
+                // WP-33: Store notification lists
+                if (command.NotificationLists != null)
+                {
+                    foreach (var nl in command.NotificationLists)
+                    {
+                        await _storage.StoreNotificationListAsync(nl.Name, nl.RecipientEmails);
+                    }
+                }
+
+                return new ArtifactDeploymentResponse(
+                    command.DeploymentId, "", true, null, DateTimeOffset.UtcNow);
+            }
+            catch (Exception ex)
+            {
+                return new ArtifactDeploymentResponse(
+                    command.DeploymentId, "", false, ex.Message, DateTimeOffset.UtcNow);
+            }
+        }).PipeTo(sender);
+    }
+
     /// <summary>
     /// Creates a child Instance Actor with the given name and configuration JSON.
     /// </summary>
@@ -333,6 +416,10 @@ public class DeploymentManagerActor : ReceiveActor, IWithTimers
             instanceName,
             configJson,
             _storage,
+            _compilationService,
+            _sharedScriptLibrary,
+            _streamManager,
+            _options,
             loggerFactory.CreateLogger<InstanceActor>()));
 
         var actorRef = Context.ActorOf(props, instanceName);