fix(sitecallaudit): push StuckOnly filter into SQL; doc accuracy fixes

src/ScadaLink.ConfigurationDatabase/Repositories/SiteCallAuditRepository.cs

@@ -164,7 +164,13 @@ WHERE TrackedOperationId = {idText}
 
         var fromUtc = filter.FromUtc;
         var toUtc = filter.ToUtc;
+        var stuckCutoff = filter.StuckCutoffUtc;
 
+        // The stuck predicate (TerminalAtUtc IS NULL AND CreatedAtUtc < cutoff)
+        // is pushed into SQL here — both columns are plain (no value converter)
+        // and compose with the keyset cursor, so a StuckOnly page is honest:
+        // never under-filled with a non-null next cursor. Mirrors how
+        // NotificationOutboxRepository.QueryAsync applies NotificationOutboxFilter.StuckCutoff.
         FormattableString sql = $@"
 SELECT TOP ({paging.PageSize})
     TrackedOperationId, Channel, Target, SourceSite, Status, RetryCount,
@@ -176,6 +182,7 @@ WHERE ({filter.Channel} IS NULL OR Channel = {filter.Channel})
   AND ({filter.Target} IS NULL OR Target = {filter.Target})
   AND ({fromUtc} IS NULL OR CreatedAtUtc >= {fromUtc})
   AND ({toUtc} IS NULL OR CreatedAtUtc <= {toUtc})
+  AND ({stuckCutoff} IS NULL OR (TerminalAtUtc IS NULL AND CreatedAtUtc < {stuckCutoff}))
   AND ({(hasCursor ? 1 : 0)} = 0
        OR CreatedAtUtc < {afterCreated}
        OR (CreatedAtUtc = {afterCreated} AND TrackedOperationId < {afterIdString}))