[BUG] Startup banner shows 'max effort' but /model selector shows 'High effort'

Bug description

The startup banner and the /model selector show different effort levels on a fresh session launch.

• Startup banner: "Opus 4.6 (1M context) with max effort · Claude Max"
• Model selector (opened immediately after): "● High effort ← → to adjust"

I have CLAUDE_CODE_EFFORT_LEVEL set to max via environment variable. The startup banner correctly reflects this ("max effort"), but the /model selector shows "High effort" instead. It's unclear which effort level is actually being used for inference since the two UI surfaces disagree.

Steps to reproduce

1. Set CLAUDE_CODE_EFFORT_LEVEL=max in your shell environment
2. Launch claude
3. Observe startup banner says "max effort"
4. Open the model selector (e.g. /model)
5. Observe it says "High effort"

Expected behavior

Both the startup banner and the model selector should show the same effort level ("max effort").

Environment

• Claude Code v2.1.83
• macOS
• CLAUDE_CODE_EFFORT_LEVEL=max set as environment variable

Related issues

• #38073 — TUI welcome screen shows stale effort after /model + /compact
• #34633 — /effort always reports "max" regardless of /model changes
• #34837 — effortLevel: 'max' not serialized to settings.json (likely root cause)
• #35155 — /model reads from settings.json, ignoring env var override
• #37773 — Status bar shows wrong effort after /effort max