feat: rebrand to MMD PDF, single corporate theme, and remove original text under an edit

- Services/PdfRedactText.cs: strip text whose origin falls inside a CoverAnnotation
  from the page content stream at save time, hooked into PdfBurn.DrawAnnotationsIntoDoc.
  Fixes edited values staying recoverable by text extraction.
- Themes/MMD.xaml replaces all thirteen themes; picker and accent strip removed; no dark mode.
- Rename KillerPDF -> MMD PDF across code, resources, packaging and locale strings; new icon.
- Remove the upstream author credit and the in-app install button.

Packaging/MmdPdfLauncher/MmdPdfLauncher.csproj

@@ -0,0 +1,36 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFramework>net48</TargetFramework>
+    <PlatformTarget>x64</PlatformTarget>
+    <LangVersion>latest</LangVersion>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>disable</ImplicitUsings>
+    <UseWindowsForms>true</UseWindowsForms>
+    <AssemblyName Condition="'$(LauncherAssemblyName)' != ''">$(LauncherAssemblyName)</AssemblyName>
+    <ApplicationIcon Condition="'$(LauncherIcon)' != ''">$(LauncherIcon)</ApplicationIcon>
+    <ApplicationManifest>app.manifest</ApplicationManifest>
+    <Version Condition="'$(LauncherVersion)' != ''">$(LauncherVersion)</Version>
+    <AssemblyVersion Condition="'$(LauncherVersion)' != ''">$(LauncherVersion).0</AssemblyVersion>
+    <FileVersion Condition="'$(LauncherVersion)' != ''">$(LauncherVersion).0</FileVersion>
+    <IncludeSourceRevisionInInformationalVersion>false</IncludeSourceRevisionInInformationalVersion>
+    <!-- The launcher only uses .NET Framework inbox assemblies, so it needs no binding redirects.
+         Disabling their generated config also keeps SDK 10 publish from looking for a config named
+         after the overridden release assembly instead of the project assembly. -->
+    <AutoGenerateBindingRedirects>false</AutoGenerateBindingRedirects>
+    <GenerateBindingRedirectsOutputType>false</GenerateBindingRedirectsOutputType>
+    <DefineConstants Condition="'$(AllowUnsignedInstall)' == 'true'">$(DefineConstants);ALLOW_UNSIGNED_INSTALL</DefineConstants>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Reference Include="System.IO.Compression" />
+  </ItemGroup>
+
+  <ItemGroup Condition="Exists('$(PayloadZip)')">
+    <EmbeddedResource Include="$(PayloadZip)" LogicalName="MmdPdfLauncher.payload.zip" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.3" PrivateAssets="all" />
+  </ItemGroup>
+</Project>