docs: add XML doc comments across src + Sister Projects section in CLAUDE.md

Bulk CommentChecker pass: fills in <param>/<inheritdoc> tags on public
APIs across all 23 src/ projects so the doc-coverage gate is green. Also
adds a Sister Projects section to CLAUDE.md pointing at the MxAccess
Gateway and OtOpcUa sibling repos, and gitignores local credential
captures (*login*.txt) and the wonder-app-vd03 deploy/ artifacts.

src/ScadaLink.Commons/Interfaces/Repositories/IAuditLogRepository.cs

@@ -29,6 +29,8 @@ public interface IAuditLogRepository
     /// stored row untouched (first-write-wins). Bypasses the EF change tracker
     /// so the row never enters a tracked state.
     /// </summary>
+    /// <param name="evt">The audit event to insert.</param>
+    /// <param name="ct">Cancellation token.</param>
     Task InsertIfNotExistsAsync(AuditEvent evt, CancellationToken ct = default);
 
     /// <summary>
@@ -39,6 +41,9 @@ public interface IAuditLogRepository
     /// <see cref="AuditLogPaging.AfterOccurredAtUtc"/> +
     /// <see cref="AuditLogPaging.AfterEventId"/> to fetch the next page.
     /// </summary>
+    /// <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>
     Task<IReadOnlyList<AuditEvent>> QueryAsync(
         AuditLogQueryFilter filter,
         AuditLogPaging paging,
@@ -75,6 +80,8 @@ public interface IAuditLogRepository
     /// and the composite PK still rejects same-(EventId, OccurredAtUtc) rows.
     /// </para>
     /// </remarks>
+    /// <param name="monthBoundary">Lower-bound datetime of the monthly partition to switch out.</param>
+    /// <param name="ct">Cancellation token.</param>
     Task<long> SwitchOutPartitionAsync(DateTime monthBoundary, CancellationToken ct = default);
 
     /// <summary>
@@ -85,6 +92,8 @@ public interface IAuditLogRepository
     /// excluded (a no-op switch is wasted work). Used by the M6 purge actor
     /// to enumerate retention-eligible months on every tick.
     /// </summary>
+    /// <param name="threshold">Only partitions whose data is entirely older than this UTC datetime are returned.</param>
+    /// <param name="ct">Cancellation token.</param>
     Task<IReadOnlyList<DateTime>> GetPartitionBoundariesOlderThanAsync(
         DateTime threshold,
         CancellationToken ct = default);
@@ -172,6 +181,8 @@ public interface IAuditLogRepository
     /// stub-node treatment of any other row-less execution.
     /// </para>
     /// </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>
     Task<IReadOnlyList<ExecutionTreeNode>> GetExecutionTreeAsync(
         Guid executionId,
         CancellationToken ct = default);
@@ -182,5 +193,6 @@ public interface IAuditLogRepository
     /// "Node" multi-select filter dropdown — the Central UI caches the result
     /// for ~60s so the repository is hit at most once per minute per circuit.
     /// </summary>
+    /// <param name="ct">Cancellation token.</param>
     Task<IReadOnlyList<string>> GetDistinctSourceNodesAsync(CancellationToken ct = default);
 }