Phase 3 PR 33 — DriverHostStatus entity + EF migration (data-layer for LMX #7). New DriverHostStatus entity with composite key (NodeId, DriverInstanceId, HostName) persists each server node's per-host connectivity view — one row per (server node, driver instance, probe-reported host), which means a redundant 2-node cluster with one Galaxy driver reporting 3 platforms produces 6 rows because each server node owns its own runtime view of the shared host topology, not 3. Fields: NodeId (64), DriverInstanceId (64), HostName (256 — fits Galaxy FQDNs and Modbus host:port strings), State (DriverHostState enum — Unknown/Running/Stopped/Faulted, persisted as nvarchar(16) via HasConversion<string> so DBAs inspecting the table see readable state names not ordinals), StateChangedUtc + LastSeenUtc (datetime2(3) — StateChangedUtc tracks actual transitions while LastSeenUtc advances on every publisher heartbeat so the Admin UI can flag stale rows from a crashed Server independent of State), Detail (nullable 1024 — exception message from the driver's probe when Faulted, null otherwise).

DriverHostState enum lives in Configuration.Enums/ rather than reusing Core.Abstractions.HostState so the Configuration project stays free of driver-runtime dependencies (it's referenced by both the Admin process and the Server process, so pulling in the driver-abstractions assembly to every Admin build would be unnecessary weight). The server-side publisher hosted service (follow-up PR 34) will translate HostStatusChangedEventArgs.NewState to this enum on every transition.
No foreign key to ClusterNode — a Server may start reporting host status before its ClusterNode row exists (first-boot bootstrap), and we'd rather keep the status row than drop it. The Admin-side service that renders the dashboard will left-join on NodeId when presenting. Two indexes declared: IX_DriverHostStatus_Node drives the per-cluster drill-down (Admin UI joins ClusterNode on ClusterId to pick which NodeIds to fetch), IX_DriverHostStatus_LastSeen drives the stale-row query (now - LastSeen > threshold).
EF migration AddDriverHostStatus creates the table + PK + both indexes. Model snapshot updated. SchemaComplianceTests expected-tables list extended. DriverHostStatusTests (3 new cases, category SchemaCompliance, uses the shared fixture DB): composite key allows same (host, driver) across different nodes AND same (node, host) across different drivers — both real-world cases the publisher needs to support; upsert-in-place pattern (fetch-by-composite-PK, mutate, save) produces one row not two — the pattern the publisher will use; State enum persists as string not int — reading the DB via ADO.NET returns 'Faulted' not '3'.
Configuration.Tests SchemaCompliance suite: 10 pass / 0 fail (7 prior + 3 new). Configuration build clean. No Server or Admin code changes yet — publisher + /hosts page are PR 34.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/ZB.MOM.WW.OtOpcUa.Configuration/Migrations/OtOpcUaConfigDbContextModelSnapshot.cs

@@ -332,6 +332,46 @@ namespace ZB.MOM.WW.OtOpcUa.Configuration.Migrations
                         });
                 });
 
+            modelBuilder.Entity("ZB.MOM.WW.OtOpcUa.Configuration.Entities.DriverHostStatus", b =>
+                {
+                    b.Property<string>("NodeId")
+                        .HasMaxLength(64)
+                        .HasColumnType("nvarchar(64)");
+
+                    b.Property<string>("DriverInstanceId")
+                        .HasMaxLength(64)
+                        .HasColumnType("nvarchar(64)");
+
+                    b.Property<string>("HostName")
+                        .HasMaxLength(256)
+                        .HasColumnType("nvarchar(256)");
+
+                    b.Property<string>("Detail")
+                        .HasMaxLength(1024)
+                        .HasColumnType("nvarchar(1024)");
+
+                    b.Property<DateTime>("LastSeenUtc")
+                        .HasColumnType("datetime2(3)");
+
+                    b.Property<string>("State")
+                        .IsRequired()
+                        .HasMaxLength(16)
+                        .HasColumnType("nvarchar(16)");
+
+                    b.Property<DateTime>("StateChangedUtc")
+                        .HasColumnType("datetime2(3)");
+
+                    b.HasKey("NodeId", "DriverInstanceId", "HostName");
+
+                    b.HasIndex("LastSeenUtc")
+                        .HasDatabaseName("IX_DriverHostStatus_LastSeen");
+
+                    b.HasIndex("NodeId")
+                        .HasDatabaseName("IX_DriverHostStatus_Node");
+
+                    b.ToTable("DriverHostStatus", (string)null);
+                });
+
             modelBuilder.Entity("ZB.MOM.WW.OtOpcUa.Configuration.Entities.DriverInstance", b =>
                 {
                     b.Property<Guid>("DriverInstanceRowId")