docs: complete XML doc coverage (returns, summaries, inheritdoc)

Resolve all 622 issues flagged by the enhanced CommentChecker: add missing
<returns> tags (incl. the standard phrasing on non-generic Task methods),
add missing <summary> tags, and replace misused/redundant <inheritdoc/> on
members that override or implement nothing with real documentation.
Documentation-only — no behavior change; solution builds clean.

src/ZB.MOM.WW.ScadaBridge.ManagementService/AuditExportRow.cs

@@ -63,6 +63,8 @@ public sealed record AuditExportRow
     public AuditForwardState? ForwardState { get; init; }
 
     /// <summary>Decomposes a canonical <see cref="AuditEvent"/> into this flat export shape.</summary>
+    /// <param name="evt">The audit event to decompose into the flat export row.</param>
+    /// <returns>A new <see cref="AuditExportRow"/> populated from the decomposed canonical row.</returns>
     public static AuditExportRow From(AuditEvent evt)
     {
         var r = AuditRowProjection.Decompose(evt);