v1.2.0: 重构为插件+独立Manager架构，横版UI，精确保留文本框边距的文档转换

Manager/ActivateDialog.xaml

@@ -0,0 +1,35 @@
+<Window x:Class="BetterSeewo.Manager.ActivateDialog"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        Title="专业版激活" Height="260" Width="440"
+        WindowStartupLocation="CenterOwner"
+        WindowStyle="SingleBorderWindow"
+        ResizeMode="NoResize"
+        FontSize="14">
+    <Window.Resources>
+        <Style TargetType="Button">
+            <Setter Property="Padding" Value="20,8"/>
+            <Setter Property="Margin" Value="8"/>
+            <Setter Property="Cursor" Value="Hand"/>
+        </Style>
+    </Window.Resources>
+    <Grid Margin="20">
+        <Grid.RowDefinitions>
+            <RowDefinition Height="Auto"/>
+            <RowDefinition Height="Auto"/>
+            <RowDefinition Height="Auto"/>
+            <RowDefinition Height="Auto"/>
+            <RowDefinition Height="*"/>
+        </Grid.RowDefinitions>
+        <TextBlock Grid.Row="0" Text="输入 Better-Seewo 专业版激活码" FontSize="16" FontWeight="SemiBold" Margin="0,0,0,16"/>
+        <TextBox Grid.Row="1" x:Name="KeyTextBox" FontSize="18" Padding="8"
+                 HorizontalAlignment="Stretch" TextChanged="OnKeyTextChanged"/>
+        <TextBlock Grid.Row="2" x:Name="HintText" Text="激活码通常由 16 位以上字母和数字组成"
+                   Foreground="Gray" FontSize="12" Margin="0,6,0,0"/>
+        <StackPanel Grid.Row="3" Orientation="Horizontal" HorizontalAlignment="Right" Margin="0,16,0,0">
+            <Button Content="取消" IsCancel="True" Width="80"/>
+            <Button x:Name="ActivateButton" Content="激活" IsDefault="True" Width="80"
+                    IsEnabled="False" Click="Activate_Click"/>
+        </StackPanel>
+    </Grid>
+</Window>