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.CLI/Commands/AuditFormatter.cs

@@ -43,6 +43,7 @@ public static class AuditFormatterFactory
     /// </summary>
     /// <param name="format">Format name; <c>table</c> selects the table formatter, any other value selects JSONL.</param>
     /// <param name="notices">Writer for notice messages emitted during formatting.</param>
+    /// <returns>The <see cref="IAuditFormatter"/> appropriate for the requested format.</returns>
     public static IAuditFormatter Create(string format, TextWriter notices)
     {
         if (string.Equals(format, "table", StringComparison.OrdinalIgnoreCase))