refactor: address code review findings across all projects

Apply comprehensive fixes from code reviews including:
- Extract shared utilities (SqlFormatHelper, CellValueConverter, DbDestinationBase)
- Add interface abstractions (IAuthenticationService, IDatabaseMigrator, IMisQueryBuilder)
- Implement SecureStore for encrypted secrets storage
- Fix error handling with proper HTTP status codes and logging
- Optimize double enumeration in DevEtlRegistry
- Add DataSync.Dev README for developer onboarding
- Extract filter panel base classes to reduce duplication
- Update code review docs to mark all issues as fixed

NEW/tests/JdeScoping.Api.Tests/Hubs/StatusHubTests.cs

@@ -1,6 +1,7 @@
 using JdeScoping.Api.Hubs;
 using JdeScoping.Core.ViewModels;
 using Microsoft.AspNetCore.SignalR;
+using Microsoft.Extensions.Caching.Memory;
 using Microsoft.Extensions.Logging;
 using NSubstitute;
 using Shouldly;
@@ -9,13 +10,17 @@ namespace JdeScoping.Api.Tests.Hubs;
 
 public class StatusHubTests
 {
+    private readonly IMemoryCache _cache;
     private readonly ILogger<StatusHub> _logger;
+    private readonly TimeProvider _timeProvider;
     private readonly StatusHub _hub;
 
     public StatusHubTests()
     {
+        _cache = new MemoryCache(new MemoryCacheOptions());
         _logger = Substitute.For<ILogger<StatusHub>>();
-        _hub = new StatusHub(_logger);
+        _timeProvider = TimeProvider.System;
+        _hub = new StatusHub(_cache, _logger, _timeProvider);
     }
 
     [Fact]
@@ -47,34 +52,33 @@ public class StatusHubTests
             "statusUpdate",
             Arg.Is<object?[]>(args => args.Length == 1 && args[0] == statusUpdate),
             Arg.Any<CancellationToken>());
+
+        // Assert - verify status was cached
+        var cachedStatus = _hub.GetCachedStatus();
+        cachedStatus.Message.ShouldBe("Processing");
     }
 
     [Fact]
     public void GetCachedStatus_ReturnsLastSetStatus()
     {
-        // The hub uses a static cached status, so this test checks the initial state
-        // Note: Due to static state, tests may affect each other if run in parallel
-
         // Act
         var status = _hub.GetCachedStatus();
 
         // Assert
         status.ShouldNotBeNull();
         // Initial message is "Unknown"
-        status.Message.ShouldNotBeNullOrEmpty();
+        status.Message.ShouldBe("Unknown");
     }
 
     [Fact]
     public void GetCachedStatus_InitialStatusIsUnknown()
     {
-        // This test verifies the default initial state
-        // Note: This test assumes no other test has modified the static state
-
         // Act
         var status = _hub.GetCachedStatus();
 
         // Assert
         status.ShouldNotBeNull();
+        status.Message.ShouldBe("Unknown");
         // The timestamp should be set
         status.Timestamp.ShouldNotBe(default);
     }