Steam 'n' Rails Create Fly 26.2 beta.3

Fixes

• Prevent startup and mod-conflict crashes caused by bundled compatibility shims colliding with Create Fly or Copycats+ classes (#1, #2).
• Stop writing Railways_DataVersion into player advancement JSON, and recover existing affected saves without discarding advancement progress (#3).
• Fix locometal sliding and folding door rendering with Iris shader packs.
• Support both Create Fly render paths: the shader-compatible block-entity renderer and the optimized Flywheel visual backend.
• Preserve solid/windowed door variants and synchronize the state between both door halves.
• Pin the supported Create Fly compatibility line and reject incompatible future 6.0.10 builds.
• Add publication checks that reject foreign Create, Registrate, Minecraft, and Forge namespaces in release JARs.