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/src/JdeScoping.Database/DatabaseMigrator.cs

@@ -4,16 +4,25 @@ using Microsoft.Extensions.Configuration;
 
 namespace JdeScoping.Database;
 
-public class DatabaseMigrator
+/// <summary>
+/// Handles database migrations using DbUp.
+/// </summary>
+public class DatabaseMigrator : IDatabaseMigrator
 {
     private readonly string _connectionString;
 
+    /// <summary>
+    /// Initializes a new instance of the DatabaseMigrator class.
+    /// </summary>
+    /// <param name="configuration">Application configuration containing connection strings.</param>
+    /// <exception cref="InvalidOperationException">Thrown when SqlServer connection string is not configured.</exception>
     public DatabaseMigrator(IConfiguration configuration)
     {
         _connectionString = configuration.GetConnectionString("SqlServer")
             ?? throw new InvalidOperationException("SqlServer connection string not configured");
     }
 
+    /// <inheritdoc />
     public DatabaseUpgradeResult Migrate()
     {
         EnsureDatabase.For.SqlDatabase(_connectionString);

NEW/src/JdeScoping.Database/IDatabaseMigrator.cs

@@ -0,0 +1,15 @@
+using DbUp.Engine;
+
+namespace JdeScoping.Database;
+
+/// <summary>
+/// Interface for database migration operations.
+/// </summary>
+public interface IDatabaseMigrator
+{
+    /// <summary>
+    /// Runs all pending database migrations.
+    /// </summary>
+    /// <returns>The result of the migration operation.</returns>
+    DatabaseUpgradeResult Migrate();
+}