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.Commons/Interfaces/Repositories/IAuditLogRepository.cs

@@ -31,6 +31,7 @@ public interface IAuditLogRepository
     /// </summary>
     /// <param name="evt">The audit event to insert.</param>
     /// <param name="ct">Cancellation token.</param>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     Task InsertIfNotExistsAsync(AuditEvent evt, CancellationToken ct = default);
 
     /// <summary>
@@ -44,6 +45,7 @@ public interface IAuditLogRepository
     /// <param name="filter">Filter criteria to apply to the query.</param>
     /// <param name="paging">Paging cursor and page size.</param>
     /// <param name="ct">Cancellation token.</param>
+    /// <returns>A task that resolves to the matching audit events for the requested page, ordered by <c>(OccurredAtUtc DESC, EventId DESC)</c>.</returns>
     Task<IReadOnlyList<AuditEvent>> QueryAsync(
         AuditLogQueryFilter filter,
         AuditLogPaging paging,
@@ -82,6 +84,7 @@ public interface IAuditLogRepository
     /// </remarks>
     /// <param name="monthBoundary">Lower-bound datetime of the monthly partition to switch out.</param>
     /// <param name="ct">Cancellation token.</param>
+    /// <returns>A task that resolves to the approximate number of rows discarded by the partition switch.</returns>
     Task<long> SwitchOutPartitionAsync(DateTime monthBoundary, CancellationToken ct = default);
 
     /// <summary>
@@ -94,6 +97,7 @@ public interface IAuditLogRepository
     /// </summary>
     /// <param name="threshold">Only partitions whose data is entirely older than this UTC datetime are returned.</param>
     /// <param name="ct">Cancellation token.</param>
+    /// <returns>A task that resolves to the list of partition lower-bound boundaries eligible for purge.</returns>
     Task<IReadOnlyList<DateTime>> GetPartitionBoundariesOlderThanAsync(
         DateTime threshold,
         CancellationToken ct = default);
@@ -183,6 +187,7 @@ public interface IAuditLogRepository
     /// </remarks>
     /// <param name="executionId">Any execution id in the chain; the implementation walks to the root and back down.</param>
     /// <param name="ct">Cancellation token.</param>
+    /// <returns>A task that resolves to the full execution tree rooted at the topmost ancestor, one node per distinct execution.</returns>
     Task<IReadOnlyList<ExecutionTreeNode>> GetExecutionTreeAsync(
         Guid executionId,
         CancellationToken ct = default);
@@ -194,5 +199,6 @@ public interface IAuditLogRepository
     /// for ~60s so the repository is hit at most once per minute per circuit.
     /// </summary>
     /// <param name="ct">Cancellation token.</param>
+    /// <returns>A task that resolves to the distinct, non-null source node names in ascending order.</returns>
     Task<IReadOnlyList<string>> GetDistinctSourceNodesAsync(CancellationToken ct = default);
 }