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/Utils/JdeScoping.SecureStoreManager/Views/SecretEditDialog.axaml

@@ -0,0 +1,50 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:vm="clr-namespace:JdeScoping.SecureStoreManager.ViewModels"
+        x:Class="JdeScoping.SecureStoreManager.Views.SecretEditDialog"
+        Title="{Binding DialogTitle}"
+        Height="280" Width="450"
+        WindowStartupLocation="CenterOwner"
+        CanResize="False"
+        ShowInTaskbar="False">
+    <Window.DataContext>
+        <vm:SecretEditDialogViewModel />
+    </Window.DataContext>
+
+    <Grid Margin="15" RowDefinitions="Auto,Auto,*,Auto">
+        <!-- Key -->
+        <Grid Grid.Row="0" ColumnDefinitions="80,*" Margin="0,0,0,10">
+            <TextBlock Grid.Column="0" Text="Key:" VerticalAlignment="Center" Margin="0,5,10,5" />
+            <TextBox Grid.Column="1"
+                     Text="{Binding Key, Mode=TwoWay}"
+                     IsEnabled="{Binding IsKeyEditable}"
+                     Margin="0,5" />
+        </Grid>
+
+        <!-- Value -->
+        <Grid Grid.Row="1" ColumnDefinitions="80,*" Margin="0,0,0,10">
+            <TextBlock Grid.Column="0" Text="Value:" VerticalAlignment="Top" Margin="0,8,10,5" />
+            <TextBox Grid.Column="1"
+                     Text="{Binding Value, Mode=TwoWay}"
+                     TextWrapping="Wrap"
+                     AcceptsReturn="True"
+                     Height="80"
+                     Margin="0,5" />
+        </Grid>
+
+        <!-- Validation Error -->
+        <TextBlock Grid.Row="2"
+                   Text="{Binding ValidationError}"
+                   Foreground="Red"
+                   FontSize="11"
+                   Margin="0,5,0,0"
+                   IsVisible="{Binding ValidationError, Converter={StaticResource StringToBool}}"
+                   VerticalAlignment="Top" />
+
+        <!-- Buttons -->
+        <StackPanel Grid.Row="3" Orientation="Horizontal" HorizontalAlignment="Right" Spacing="10">
+            <Button Content="Save" Click="SaveButton_Click" MinWidth="80" Padding="10,5" />
+            <Button Content="Cancel" Click="CancelButton_Click" MinWidth="80" Padding="10,5" />
+        </StackPanel>
+    </Grid>
+</Window>