Follow up of #292 (comment)

The controllers (SandboxReconciler, SandboxClaimReconciler, SandboxWarmPoolReconciler) run concurrently via controller-runtime. If reconcilers share mutable state without proper synchronization, data races can occur. The codebase already includes pprof block/mutex profiling under --enable-pprof-debug , which helps diagnose contention but does not detect data races.

TODOs:

• Update dev/tools/test-unit and dev/tools/test-e2e to add -race
• Update dev doc to note race detection usage and runtime overhead caveats
• Verify CI passes with -race enabled; fix any detected races