Statusline doesn't update after /model command

Description

After using the /model command to switch models, the statusline and header continue to display the previous model name instead of the newly selected model.

Steps to Reproduce

1. Start Claude Code (was showing "Haiku 4.5" in statusline)
2. Run /model command
3. Select "Default (Opus 4.5 · Most capable for complex work)"
4. Command confirms: "Set model to Default (Opus 4.5 · Most capable for complex work)"

Expected Behavior

Statusline and header should update to show "Opus 4.5"

Actual Behavior

• Statusline still shows "Haiku 4.5"
• Header still shows "Haiku 4.5 · Claude Max"

Note: The model switch itself appears to work correctly (responses come from Opus 4.5), only the UI display is stale.

Environment

• Claude Code version: v2.1.19
• Plan: Claude Max
• OS: macOS