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.AuditLog/Redaction/ScadaBridgeAuditRedactor.cs

@@ -73,7 +73,12 @@ public sealed class ScadaBridgeAuditRedactor : IAuditRedactor
         _regexCache = new AuditRegexCache(_logger);
     }
 
-    /// <inheritdoc />
+    /// <summary>
+    /// Applies the full redaction pipeline to <paramref name="rawEvent"/> and returns a
+    /// filtered copy; returns the same instance unchanged on the fast path. Never throws.
+    /// </summary>
+    /// <param name="rawEvent">The raw audit event to redact.</param>
+    /// <returns>A redacted copy of <paramref name="rawEvent"/>, or the original instance when no changes are needed.</returns>
     public AuditEvent Apply(AuditEvent rawEvent)
     {
         try