Refactor: Convert envelope query filters to LINQ query syntax

- Replaced multiple sequential 'Where' calls with a single LINQ query expression
- Preserved all status filters (Include, Ignore, Min, Max)
- Preserved DocResult filtering logic
- Improves readability while keeping behavior identical

EnvelopeGenerator.Application/Envelopes/Queries/ReadEnvelopeQuery.cs

@@ -107,33 +107,21 @@ public class ReadEnvelopeQueryHandler : IRequestHandler<ReadEnvelopeQuery, IEnum
     /// <exception cref="NotImplementedException"></exception>
     public async Task<IEnumerable<EnvelopeDto>> Handle(ReadEnvelopeQuery request, CancellationToken cancel)
     {
-        var q = _repo.Query.Where(request, notnull: false);
+        var envelopesQ = _repo.Query.Where(request, notnull: false);
 
-        if (request.Status is EnvelopeStatusQuery statusQ)
+        EnvelopeStatusQuery? statusQ = request.Status;
-        {
+        bool? hasDocResult = request.HasDocResult;
-            // including status
-            if (statusQ.Include is EnvelopeStatus[] incStatus)
-                q = q.Where(e => incStatus.Contains(e.Status));
 
-            // ignoring status
+        var filtered =
-            if (statusQ.Ignore is EnvelopeStatus[] ignoreStatus)
+            from envelope in envelopesQ
-                q = q.Where(e => !ignoreStatus.Contains(e.Status));
+            where (statusQ == null || statusQ.Include == null || statusQ.Include.Contains(envelope.Status))
+               && (statusQ == null || statusQ.Ignore == null || !statusQ.Ignore.Contains(envelope.Status))
+               && (statusQ == null || statusQ.Min == null || envelope.Status > statusQ.Min)
+               && (statusQ == null || statusQ.Max == null || envelope.Status < statusQ.Max)
+               && (!hasDocResult.HasValue || (hasDocResult.Value ? envelope.DocResult != null : envelope.DocResult == null))
+            select envelope;
 
-            // max status
+        var envelopes = await filtered.ToListAsync(cancel);
-            if (statusQ.Max is EnvelopeStatus maxStatus)
-                q = q.Where(e => e.Status < maxStatus);
-
-            // min status
-            if (statusQ.Min is EnvelopeStatus minStatus)
-                q = q.Where(e => e.Status > minStatus);
-        }
-
-        if (request.HasDocResult is bool hasDocResult)
-            q = hasDocResult
-                ? q.Where(e => e.DocResult != null)
-                : q.Where(e => e.DocResult == null);
-
-        var envelopes = await q.ToListAsync(cancel);
 
         return _mapper.Map<IEnumerable<EnvelopeDto>>(envelopes);
     }