fix(adminui): Galaxy editor 500 — read DriverConfig case-insensitively + null-safe FromRecord

GalaxyDriverPage deserialized DriverConfig with case-sensitive camelCase opts, but the
persisted/seeded config is PascalCase (the runtime reads it case-insensitively). So all four
nested option records read as null -> FromRecord NRE (HTTP 500) on edit, and the form would
have shown defaults instead of the real config (risking a clobber on save). Fix: add
PropertyNameCaseInsensitive=true (matches the runtime) so real values load, plus null-coalesce
the nested records in FromRecord as defense-in-depth. Regression test asserts the seeded
PascalCase config loads its real values.

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Clusters/Drivers/GalaxyDriverPage.razor

@@ -215,6 +215,7 @@ else
     private static readonly System.Text.Json.JsonSerializerOptions _jsonOpts = new()
     {
         PropertyNamingPolicy = System.Text.Json.JsonNamingPolicy.CamelCase,
+        PropertyNameCaseInsensitive = true,
         UnmappedMemberHandling = System.Text.Json.Serialization.JsonUnmappedMemberHandling.Skip,
         WriteIndented = false,
     };
@@ -408,26 +409,36 @@ else
         // GalaxyDriverOptions top-level
         public int ProbeTimeoutSeconds { get; set; } = 30;
 
-        public static GalaxyFormModel FromRecord(GalaxyDriverOptions r) => new()
+        public static GalaxyFormModel FromRecord(GalaxyDriverOptions r)
         {
-            GatewayEndpoint = r.Gateway.Endpoint,
-            GatewayApiKeySecretRef = r.Gateway.ApiKeySecretRef,
-            GatewayUseTls = r.Gateway.UseTls,
-            GatewayCaCertificatePath = r.Gateway.CaCertificatePath,
-            GatewayConnectTimeoutSeconds = r.Gateway.ConnectTimeoutSeconds,
-            GatewayDefaultCallTimeoutSeconds = r.Gateway.DefaultCallTimeoutSeconds,
-            GatewayStreamTimeoutSeconds = r.Gateway.StreamTimeoutSeconds,
-            MxClientName = r.MxAccess.ClientName,
-            MxPublishingIntervalMs = r.MxAccess.PublishingIntervalMs,
-            MxWriteUserId = r.MxAccess.WriteUserId,
-            MxEventPumpChannelCapacity = r.MxAccess.EventPumpChannelCapacity,
-            RepositoryDiscoverPageSize = r.Repository.DiscoverPageSize,
-            RepositoryWatchDeployEvents = r.Repository.WatchDeployEvents,
-            ReconnectInitialBackoffMs = r.Reconnect.InitialBackoffMs,
-            ReconnectMaxBackoffMs = r.Reconnect.MaxBackoffMs,
-            ReconnectReplayOnSessionLost = r.Reconnect.ReplayOnSessionLost,
-            ProbeTimeoutSeconds = r.ProbeTimeoutSeconds,
-        };
+            // Null-coalesce each nested record to its default so that persisted configs
+            // that pre-date a section (e.g. no Reconnect key, or PascalCase keys that
+            // don't match the camelCase deserializer) don't cause a NullReferenceException.
+            var gw   = r.Gateway    ?? new GalaxyGatewayOptions("https://localhost:5001", "env:MX_API_KEY");
+            var mx   = r.MxAccess   ?? new GalaxyMxAccessOptions("OtOpcUa");
+            var repo = r.Repository ?? new GalaxyRepositoryOptions();
+            var rc   = r.Reconnect  ?? new GalaxyReconnectOptions();
+            return new()
+            {
+                GatewayEndpoint = gw.Endpoint,
+                GatewayApiKeySecretRef = gw.ApiKeySecretRef,
+                GatewayUseTls = gw.UseTls,
+                GatewayCaCertificatePath = gw.CaCertificatePath,
+                GatewayConnectTimeoutSeconds = gw.ConnectTimeoutSeconds,
+                GatewayDefaultCallTimeoutSeconds = gw.DefaultCallTimeoutSeconds,
+                GatewayStreamTimeoutSeconds = gw.StreamTimeoutSeconds,
+                MxClientName = mx.ClientName,
+                MxPublishingIntervalMs = mx.PublishingIntervalMs,
+                MxWriteUserId = mx.WriteUserId,
+                MxEventPumpChannelCapacity = mx.EventPumpChannelCapacity,
+                RepositoryDiscoverPageSize = repo.DiscoverPageSize,
+                RepositoryWatchDeployEvents = repo.WatchDeployEvents,
+                ReconnectInitialBackoffMs = rc.InitialBackoffMs,
+                ReconnectMaxBackoffMs = rc.MaxBackoffMs,
+                ReconnectReplayOnSessionLost = rc.ReplayOnSessionLost,
+                ProbeTimeoutSeconds = r.ProbeTimeoutSeconds,
+            };
+        }
 
         public GalaxyDriverOptions ToRecord() => new(
             Gateway: new GalaxyGatewayOptions(