feat(deploy): surface connection-level changes in the deployment diff (#10)

ComputeConnectionsDiff existed with tests but was never called and ConfigurationDiff
had no slot for it, so standalone connection endpoint/protocol/failover drift never
appeared in the deployment diff (only per-attribute binding drift did). Add a
ConnectionChanges slot, wire ComputeConnectionsDiff into ComputeDiff, and render the
connection section in the deployment diff UI.

src/ZB.MOM.WW.ScadaBridge.Commons/Types/Flattening/ConfigurationDiff.cs

@@ -12,8 +12,8 @@ public sealed record ConfigurationDiff
     public string? OldRevisionHash { get; init; }
     /// <summary>Revision hash of the new configuration being compared.</summary>
     public string? NewRevisionHash { get; init; }
-    /// <summary>True when any attribute, alarm, or script changes are present.</summary>
-    public bool HasChanges => AttributeChanges.Count > 0 || AlarmChanges.Count > 0 || ScriptChanges.Count > 0;
+    /// <summary>True when any attribute, alarm, script, or connection changes are present.</summary>
+    public bool HasChanges => AttributeChanges.Count > 0 || AlarmChanges.Count > 0 || ScriptChanges.Count > 0 || ConnectionChanges.Count > 0;
 
     /// <summary>Diff entries for resolved attributes.</summary>
     public IReadOnlyList<DiffEntry<ResolvedAttribute>> AttributeChanges { get; init; } = [];
@@ -21,6 +21,13 @@ public sealed record ConfigurationDiff
     public IReadOnlyList<DiffEntry<ResolvedAlarm>> AlarmChanges { get; init; } = [];
     /// <summary>Diff entries for resolved scripts.</summary>
     public IReadOnlyList<DiffEntry<ResolvedScript>> ScriptChanges { get; init; } = [];
+
+    /// <summary>
+    /// Diff entries for connection configurations, keyed by connection name.
+    /// Surfaces standalone endpoint/protocol/failover drift that does not show
+    /// up as a per-attribute binding change (TemplateEngine-018).
+    /// </summary>
+    public IReadOnlyList<DiffEntry<ConnectionConfig>> ConnectionChanges { get; init; } = [];
 }
 
 /// <summary>