refactor(skill): unify PTO ISA adaptation and cross-model validation

[jiale-wangOwO]

Summary

• replace the retired linx-cross-model-validation utility with linx-qemu-gfrun-isa-adaptation;
• fold current cross-model runner, QEMU transport preflight, ELF result observation, independent golden comparison, provenance, failure classification, and optional gfsim parity into the new skill;
• document PTO ISA v0.58 profile-level adaptation, Tile-state observation, PE-local encoding, fail-closed legality, and matrix promotion rules;
• update the managed utility registry and installer metadata.

Validation

• quick_validate.py linx-qemu-gfrun-isa-adaptation
• check_skill_change_scope.py --base origin/main
• git diff --check
• canonical installer check: new utility installed and retired utility absent

This PR intentionally does not include QEMU or SuperScalarModel source changes.