Raise on LazyTurtle materialization failures and silence expected skips

[ZX-ModelCloud]

Summary

Raise on LazyTurtle materialization failures and silence expected skips

What Changed

• raise RuntimeError when LazyTurtle hits actual materialization failures:
  • resolved checkpoint tensor points to a missing shard
  • checkpoint tensor cannot be transformed into the target layout
  • transformed tensor shape still mismatches the target tensor
  • target parameter disappears before materialization
• keep normal skip paths as silent no-ops when no checkpoint tensor mapping exists