docs: fill missing XML docs and strip tracking IDs from src comments

Clears CommentChecker findings in src/ (3,280 -> 209, the remainder being false
positives like PLC-5/IEEE-754/M0.0) by adding missing summaries/params/returns,
normalising inheritdoc usage, and removing Gitea/review tracking IDs while keeping
the rationale they annotated. Comment-only: comment-stripped sources are identical
to the parent commit.

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/ContextMenuItem.cs

@@ -29,5 +29,6 @@ public sealed class ContextMenuItem
     public bool IsSeparator { get; init; }
 
     /// <summary>A horizontal divider between groups of items.</summary>
+    /// <returns>A separator menu item.</returns>
     public static ContextMenuItem Separator() => new() { IsSeparator = true };
 }