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.HealthMonitoring/ICentralHealthAggregator.cs

@@ -0,0 +1,40 @@
+using ZB.MOM.WW.ScadaBridge.Commons.Messages.Health;
+
+namespace ZB.MOM.WW.ScadaBridge.HealthMonitoring;
+
+/// <summary>
+/// Interface for central-side health aggregation.
+/// Consumed by Central UI to display site health dashboards.
+/// </summary>
+public interface ICentralHealthAggregator
+{
+    /// <summary>
+    /// Processes an incoming health report from a site and updates the aggregated state.
+    /// </summary>
+    /// <param name="report">The health report received from the site.</param>
+    void ProcessReport(SiteHealthReport report);
+
+    /// <summary>
+    /// Bumps the last-seen timestamp for a site, keeping it marked online
+    /// between full 30s reports when heartbeats are arriving — protects against
+    /// the offline threshold firing on a transiently delayed report. Heartbeat
+    /// cadence is owned by the Cluster Infrastructure / <c>SiteCommunicationActor</c>
+    /// (the application-level heartbeat to central, sent every
+    /// <c>CommunicationOptions.TransportHeartbeatInterval</c> — 5s by default);
+    /// the 60s <see cref="HealthMonitoringOptions.OfflineTimeout"/> therefore
+    /// tolerates several missed heartbeats. A heartbeat for a site with no
+    /// aggregator state yet (e.g. just after a central restart/failover)
+    /// registers that site as online with no
+    /// <see cref="SiteHealthState.LatestReport"/>, so reachable sites are not
+    /// shown as "unknown" during the failover window.
+    /// </summary>
+    /// <param name="siteId">The string identifier of the site that sent the heartbeat.</param>
+    /// <param name="receivedAt">The UTC timestamp when the heartbeat was received.</param>
+    void MarkHeartbeat(string siteId, DateTimeOffset receivedAt);
+
+    /// <summary>Returns a snapshot of all currently tracked site health states.</summary>
+    IReadOnlyDictionary<string, SiteHealthState> GetAllSiteStates();
+    /// <summary>Returns the current health state for the specified site, or null if not tracked.</summary>
+    /// <param name="siteId">The string identifier of the site to look up.</param>
+    SiteHealthState? GetSiteState(string siteId);
+}