feat: wire SQLite replication between site nodes and fix ConfigurationDatabase tests

Add SiteReplicationActor (runs on every site node) to replicate deployed
configs and store-and-forward buffer operations to the standby peer via
cluster member discovery and fire-and-forget Tell. Wire ReplicationService
handler and pass replication actor to DeploymentManagerActor singleton.

Fix 5 pre-existing ConfigurationDatabase test failures: RowVersion NOT NULL
on SQLite, stale migration name assertion, and seed data count mismatch.

tests/ScadaLink.ConfigurationDatabase.Tests/ConcurrencyTests.cs

@@ -22,12 +22,15 @@ public class ConcurrencyTestDbContext : ScadaLinkDbContext
     {
         base.OnModelCreating(modelBuilder);
 
-        // Replace the SQL Server RowVersion with an explicit concurrency token for SQLite
-        // Remove the shadow RowVersion property and add a visible ConcurrencyStamp
+        // Replace the SQL Server RowVersion with an explicit concurrency token for SQLite.
+        // SQLite can't auto-generate rowversion, so disable it and use Status as the token instead.
         modelBuilder.Entity<DeploymentRecord>(builder =>
         {
-            // The shadow RowVersion property from the base config doesn't work in SQLite.
-            // Instead, use Status as a concurrency token for the test.
+            builder.Property(d => d.RowVersion)
+                .IsRequired(false)
+                .IsConcurrencyToken(false)
+                .ValueGeneratedNever();
+
             builder.Property(d => d.Status).IsConcurrencyToken();
         });
     }