build(deps): declare Alpine runtime identifier

CaddyManager/CaddyManager.csproj

@@ -20,6 +20,12 @@
         <!-- No localized content, so skip loading ICU entirely (alpine ships no ICU anyway) -->
         <InvariantGlobalization>true</InvariantGlobalization>
         <ContainerBaseImage>mcr.microsoft.com/dotnet/aspnet:10.0-alpine</ContainerBaseImage>
+        <!--
+            The alpine base is musl. Declared here so a plain `dotnet restore` evaluates the
+            same RID the container publish uses, keeping packages.lock.json consistent for
+            CI's locked-mode restore (otherwise NU1004).
+        -->
+        <RuntimeIdentifiers>linux-musl-x64</RuntimeIdentifiers>
     </PropertyGroup>
 
     <ItemGroup>