[BUG] Skill frontmatter model field ignored in VSCode Extension (works in CLI)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

When a skill has a model field in its frontmatter (e.g. model: haiku), Claude Code CLI correctly switches to the specified model when the skill is invoked. The Claude Code VSCode Extension ignores this field and always uses the session-level model instead.

<img width="1120" height="427" alt="Image" src="https://github.com/user-attachments/assets/71cc5a0f-dd59-491b-baf6-97092fe3506a" />

What Should Happen?

Both the CLI and VSCode Extension should respect the model field in skill frontmatter and dispatch the skill to the specified model, regardless of the session-level model setting.

Error Messages/Logs

No error is thrown. The VSCode Extension silently ignores the frontmatter `model` field and responds using the session model.

Steps to Reproduce

1. Create a skill with model: haiku in frontmatter:

---
name: model-probe
description: Diagnostic skill to test model override
model: haiku
---
Report your self-identified model name.

1. Set session model to Opus 4.6 via /model
2. Invoke the skill (/model-probe) in Claude Code CLI → responds as claude-haiku-4-5-20251001 (correct)
3. Invoke the same skill (/model-probe) in Claude Code VSCode Extension → responds as claude-opus-4-6 (incorrect — session model used instead)

Claude Model

Not sure / Multiple models

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.101

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

This mirrors the documented CLI-only limitation of allowed-tools frontmatter:

"The allowed-tools frontmatter field in SKILL.md is only supported when using Claude Code CLI directly."

However, the model field has no such disclaimer in the documentation. This either needs to be fixed (make VSCode respect it) or documented (add a CLI-only note).

Confirmed with a controlled test: same skill, same session model (Opus 4.6), invoked in both environments simultaneously. CLI dispatched Haiku; VSCode stayed on Opus 4.6.