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/AuditLogPartitionMaintenanceService.cs

@@ -76,7 +76,12 @@ public sealed class AuditLogPartitionMaintenanceService : IHostedService, IDispo
         _logger = logger ?? throw new ArgumentNullException(nameof(logger));
     }
 
-    /// <inheritdoc />
+    /// <summary>
+    /// Starts the background maintenance loop, firing an immediate first tick and then
+    /// repeating every <see cref="AuditLogPartitionMaintenanceOptions.IntervalSeconds"/>.
+    /// </summary>
+    /// <param name="ct">Cancellation token provided by the host.</param>
+    /// <returns>A completed task; the loop runs independently on a background thread.</returns>
     public Task StartAsync(CancellationToken ct)
     {
         // Linked CTS lets StopAsync's cancellation AND the host's shutdown
@@ -136,14 +141,21 @@ public sealed class AuditLogPartitionMaintenanceService : IHostedService, IDispo
         }
     }
 
-    /// <inheritdoc />
+    /// <summary>
+    /// Signals the maintenance loop to stop by cancelling its linked token,
+    /// then returns the loop task so the host can await its completion.
+    /// </summary>
+    /// <param name="ct">Cancellation token provided by the host (unused — the internal CTS is cancelled directly).</param>
+    /// <returns>The background loop task, or a completed task if the loop was never started.</returns>
     public Task StopAsync(CancellationToken ct)
     {
         _cts?.Cancel();
         return _loop ?? Task.CompletedTask;
     }
 
-    /// <inheritdoc />
+    /// <summary>
+    /// Disposes the internal <see cref="CancellationTokenSource"/> used to stop the maintenance loop.
+    /// </summary>
     public void Dispose()
     {
         _cts?.Dispose();