Claude Code billing bug triggered by "HERMES.md" in git commits

User u/alexxxklepa on r/ClaudeAI reports that including the exact string "HERMES.md" (uppercase, with `.md` extension) in a git commit message causes Claude Code to ignore the user's Max 20x subscription quota and bill at API rates instead. The user, who pays $200/month for the Max plan, was charged $200.98 in extra usage before diagnosing the issue through hours of binary-search debugging across repos and commit history. Anthropic's support acknowledged the bug as an "authentication routing issue" three separate times but declined to issue a refund. The bug is notable because `HERMES.md` is a real convention used in AI agent projects as a system prompt specification file.