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.InboundAPI/ForbiddenApiChecker.cs

@@ -96,6 +96,7 @@ public static class ForbiddenApiChecker
     /// An empty list means the script is acceptable.
     /// </summary>
     /// <param name="scriptCode">The C# script source to analyse.</param>
+    /// <returns>A list of trust-model violation messages; empty if the script is clean.</returns>
     public static IReadOnlyList<string> FindViolations(string scriptCode)
     {
         if (string.IsNullOrWhiteSpace(scriptCode))