[Bug] Skill frontmatter model override not applied at runtime

Bug Description
/feedback "SKILL.md model: frontmatter is not honored at runtime for inline
skill invocation. Docs (skills reference, line ~238) state: 'Model to use when
this skill is active. The override applies for the rest of the current turn.'
In practice, a 60-day audit of session transcripts in this project
(~/.claude/projects/-Users-chaddrew-code-looper-systems/) shows zero
haiku-model tokens despite two skills (ai-newsletter-parser, schema-verify)
carrying model: haiku frontmatter since 2026-06-12. Both skills instead ran
on whatever model the calling session was set to (claude-sonnet-4-6 or
claude-fable-5 observed). Sonnet-pinned skills (looper-content-seeder,
loncaro-benchmark, techstack-brain) showed the same pattern, frequently
running on Opus instead of the pinned sonnet. Expected: skill invocation
should override the session model per the documented behavior. Actual: session
model is used regardless of the skill's model: field. This breaks
cost-routing strategies that rely on per-skill model pins."

Environment Info

• Platform: darwin
• Terminal: Apple_Terminal
• Version: 2.1.197
• Feedback ID: 53076972-695c-4182-9bc0-fec4944ceb3a

Errors

[]