Four tasks: mtime cache-bust token + tests; install & gate Django Debug Toolbar dev-only; profile + fix N+1 on /; profile + fix N+1 on /payroll/ (all four tabs) with before/after summary in the final commit message. Execute via subagent-driven-development. Auto mode — no mid-execution checkpoints. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>