refactor: rename ScadaLink → ZB.MOM.WW.ScadaBridge (code + projects + namespaces)

Solution + 23 src projects + 26 test projects renamed; folders, csproj,
namespaces, and ScadaLinkDbContext/ScadaBridgeDbContext class updated.
ActorSystem "scadalink" → "scadabridge", Akka seed-node URLs migrated.
SQL roles/logins, LDAP domains, CLI command name, and CLI config dir
(~/.scadalink → ~/.scadabridge) also renamed.

Build green; 5 Host.Tests fail awaiting SQL login rename in next commit.
Pre-existing StaleTagMonitor timing flakes unchanged.

Rename script committed at tools/rename-to-scadabridge.sh.

src/ZB.MOM.WW.ScadaBridge.NotificationOutbox/Messages/InternalMessages.cs

@@ -0,0 +1,81 @@
+using Akka.Actor;
+
+namespace ZB.MOM.WW.ScadaBridge.NotificationOutbox.Messages;
+
+/// <summary>
+/// Actor-internal message types for the <see cref="NotificationOutboxActor"/>. These are
+/// never sent across the network — they bridge the actor's async repository/delivery work
+/// back onto the actor's own mailbox so handlers run single-threaded on the actor.
+/// </summary>
+internal static class InternalMessages
+{
+    /// <summary>
+    /// Result of an asynchronous ingest persistence attempt, piped back to the actor.
+    /// Carries the original <paramref name="Sender"/> so the actor can ack the site that
+    /// submitted the notification once the insert completes.
+    /// </summary>
+    /// <param name="NotificationId">Id of the notification that was submitted.</param>
+    /// <param name="Sender">Original submitter to receive the ack.</param>
+    /// <param name="Succeeded">
+    /// True if persistence completed without error — covers both a fresh insert and an
+    /// already-existing row (idempotent re-submission). False only when the repository threw.
+    /// </param>
+    /// <param name="Error">Failure detail when <paramref name="Succeeded"/> is false; otherwise null.</param>
+    internal sealed record IngestPersisted(
+        string NotificationId,
+        IActorRef Sender,
+        bool Succeeded,
+        string? Error);
+
+    /// <summary>
+    /// Periodic tick that triggers a dispatch sweep. Started as a periodic timer in
+    /// <c>PreStart</c> at the configured <c>DispatchInterval</c>. A singleton instance is
+    /// reused so the timer carries no per-tick state.
+    /// </summary>
+    internal sealed class DispatchTick
+    {
+        /// <summary>The shared singleton tick instance scheduled by the dispatch timer.</summary>
+        internal static readonly DispatchTick Instance = new();
+
+        private DispatchTick() { }
+    }
+
+    /// <summary>
+    /// Completion signal for an asynchronous dispatch sweep, piped back to the actor so the
+    /// in-flight guard is cleared on the actor thread. Sent on both success and failure of
+    /// the sweep — the actor only needs to know the sweep has finished.
+    /// </summary>
+    internal sealed class DispatchComplete
+    {
+        /// <summary>The shared singleton completion instance.</summary>
+        internal static readonly DispatchComplete Instance = new();
+
+        private DispatchComplete() { }
+    }
+
+    /// <summary>
+    /// Periodic tick that triggers a purge sweep of terminal notification rows. Started as a
+    /// periodic timer in <c>PreStart</c> at the configured <c>PurgeInterval</c>. A singleton
+    /// instance is reused so the timer carries no per-tick state.
+    /// </summary>
+    internal sealed class PurgeTick
+    {
+        /// <summary>The shared singleton tick instance scheduled by the purge timer.</summary>
+        internal static readonly PurgeTick Instance = new();
+
+        private PurgeTick() { }
+    }
+
+    /// <summary>
+    /// Completion signal for an asynchronous purge sweep, piped back to the actor so the
+    /// sweep's outcome (logged in the pipe projection) is observed on the actor thread.
+    /// Sent on both success and failure of the sweep.
+    /// </summary>
+    internal sealed class PurgeComplete
+    {
+        /// <summary>The shared singleton completion instance.</summary>
+        internal static readonly PurgeComplete Instance = new();
+
+        private PurgeComplete() { }
+    }
+}