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/Central/IPullAuditEventsClient.cs

@@ -41,6 +41,7 @@ public interface IPullAuditEventsClient
     /// <param name="sinceUtc">Only events with an <c>OccurredAtUtc</c> at or after this cursor time are returned.</param>
     /// <param name="batchSize">Maximum number of events to return per call.</param>
     /// <param name="ct">Cancellation token.</param>
+    /// <returns>A task that resolves to the next reconciliation batch with a <c>MoreAvailable</c> flag.</returns>
     Task<PullAuditEventsResponse> PullAsync(
         string siteId,
         DateTime sinceUtc,