C:/Program Files/Git/resume causes gateway error when modelOverrides are configured — re-selecting model fixes it

Environment

• Claude Code version: latest
• Platform: Windows 11 Enterprise + macOS
• Backend: Corporate LMG gateway (Bedrock IL2) via ANTHROPIC_BASE_URL
• modelOverrides configured in settings.json mapping canonical ids to deployment-specific ids

Describe the bug

When using /resume to restore a previous session, Claude Code emits a gateway error immediately on startup. The error appears to be the model being resolved before modelOverrides and env vars are fully applied, causing a canonical or bare alias id to be sent to the gateway instead of the mapped deployment id.

Manually re-selecting the same model (e.g. /model sonnet) after /resume immediately fixes the issue — the override map resolves correctly and subsequent requests succeed.

Reproduction steps

1. Configure modelOverrides in settings.json mapping canonical ids to backend-specific deployment ids (e.g. "claude-sonnet-4-6": "claude-4-6-sonnet-aws-comm-il2[1m]")
2. Set ANTHROPIC_BASE_URL to a non-Anthropic gateway
3. Start a session, have a conversation, exit
4. Run /resume to restore the session
5. Observe gateway error on the first request

Expected behavior

/resume restores the session with model overrides fully applied, first request succeeds.

Actual behavior

Gateway error (400 or connection failure) on first request after /resume. Re-selecting the model with /model <name> immediately fixes it.

Workaround

Run /model sonnet (or your default) immediately after every /resume.