[HIGH] Unsafe environment variable mutation without synchronization in `src/setup/wizar

[ironclaw-ci]

[HIGH:75] Issue Found by Staging CI Review

Severity: HIGH
Confidence: 75/100
PR comment: #807 (comment)

Description

Unsafe environment variable mutation without synchronization in src/setup/wizard.rs. unsafe { std::env::set_var() } and remove_var() mutate global state; concurrent tests cause data races.

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Auto-created by staging-ci Claude Code review

[henrypark133]

Triage verdict: Stale (fixed)

Tests now properly synchronize using the shared ENV_MUTEX lock from src/config/helpers.rs, added in commit 3a2989d. The unsafe set_var/remove_var calls in EnvGuard are protected by the test-only mutex lock.