[BUG] VSCode extension: Default model picker shows Opus 4.6 but sets claude-sonnet-4-6

Description

When opening the model picker in the VSCode extension and selecting Default (recommended), the picker label reads "Opus 4.6 with 1M context [NEW] · Most capable for complex work" — but the resulting status message shows Set model to claude-sonnet-4-6, not Opus.

According to the Claude Code model configuration docs, on Max plan the default alias should resolve to Opus 4.6. It is resolving to Sonnet 4.6 instead.

Steps to Reproduce

1. Open Claude Code in VSCode on a Max plan account
2. Click the model picker
3. Select Default (recommended) (labeled "Opus 4.6 with 1M context [NEW]")
4. Observe the output in the chat: Set model to claude-sonnet-4-6

Expected Behavior

default on Max plan should set the model to claude-opus-4-6 (or claude-opus-4-6[1m]).

Actual Behavior

The model is set to claude-sonnet-4-6 despite the user being on Max plan and the UI label explicitly saying "Opus 4.6".

Note: When selecting Sonnet explicitly, the output reads Set model to sonnet (claude-sonnet-4-6) — with the alias shown. When selecting Default it shows Set model to claude-sonnet-4-6 — no alias, just raw model ID — suggesting the Default option has a stale hardcoded model ID.

Workaround

Set claudeCode.selectedModel to opus[1m] in VSCode settings.json and restart the session.

Environment

• Claude Code VSCode extension version: 2.1.78
• OS: macOS Darwin 24.6.0
• Account tier: Max