Remove legacy customization icon assemblies for Revit 2027 / .NET 10

[Copilot]

Revit 2027 moves Rhythm onto .NET 10, where the legacy resource loading path behind the shipped customization/icon DLLs throws at runtime. The most visible failure was Batch.UpgradeFamilies, but the underlying issue affected any node path that loaded those assemblies.

• What changed

  • Removed deploy/2027/RhythmCore.customization.dll and deploy/2027/RhythmRevit.customization.dll
  • Stopped generating customization/icon DLLs for Revit 2027 in RhythmCore and RhythmRevit
  • Updated RhythmViewExtension to skip downloading those DLLs for 2027 and delete stale local copies if present

• Runtime behavior

  • Revit 2027 continues to load the main node libraries and customization XML
  • Legacy icon assemblies are no longer part of the 2027 package/runtime path
  • This avoids the .NET 10 BinaryFormatter failure without changing node execution logic

• Legacy serialization cleanup

  • Removed obsolete exception serialization members tied to legacy formatter-based patterns
  • Removed BinaryFormatter-specific text from the resx scaffolding/helpers and checked-in resx comments

• Documentation

  • Added a short README note that Revit 2027 no longer ships the legacy customization DLLs

Example of the packaging/build change:

<Target Name="CreateNodeIcons" AfterTargets="PostBuildEvent" Condition="'$(RevitVersion)' != '2027'">

And the runtime guard in the view extension:

if (ShouldSkipCustomizationDll(version))
{
    return;
}