[Feature Request] Merge /simplify and /security-review commands into unified /codereview command

Bug Description
/simplify and /security-review should be merged into /codedereview or something like that, the same flow, just one more point to look at
should also happen at the same time

Environment Info

• Platform: linux
• Terminal: alacritty
• Version: 2.1.63
• Feedback ID: 747a54ad-355a-49bc-981f-b49a05cb8a2c

Errors

[{"error":"Error: NON-FATAL: Lock acquisition failed for /home/user/.local/share/claude/versions/2.1.63 (expected in multi-process scenarios)\n    at oN$ (/$bunfs/root/claude:2435:2100)\n    at URA (/$bunfs/root/claude:2435:1211)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-02-28T14:17:20.072Z"}]