/model picker does not list newly available models (Opus 4.7, 4.8)

Description

The /model picker does not include newly released models, even though the CLI banner advertises them at startup.

Steps to Reproduce

1. Start a new Claude Code session (v2.1.156, Claude Team plan)
2. Observe the startup banner: Opus 4.8 is now available! · /model to switch
3. Type /model
4. The picker list does not include Opus 4.8 (or previously, 4.7)

Expected Behavior

Models advertised in the startup banner should appear in the /model picker.

Actual Behavior

The picker omits the advertised model. This has happened consistently across multiple model releases (4.7 and now 4.8).

Environment

• Claude Code version: 2.1.156
• Plan: Claude Team
• OS: Linux 6.17.0-29-generic
• TUI mode: fullscreen

Workaround

Setting "model": "claude-opus-4-8" in ~/.claude/settings.json works, but the picker should list all available models.