The `-h|--help` case ran `sed -n '2,55p' "$0"`, but the script cd's to the
repo root before arg-parsing — so a relative-path invocation from another
cwd left `$0` unresolvable and (under set -e) `--help` printed nothing. It
also dumped raw #-comment lines and truncated at line 55, omitting the
endpoint-first + env-override sections.
Replace with a `usage()` heredoc: cwd-independent, complete (all flags + env
overrides + examples), cleanly formatted. `-h` and `--help` both print it.
Claude-Session: https://claude.ai/code/session_01EfF565T9eSLaqGzidyJ1Pm
Co-authored-by: noonghunna <10742901+noonghunna@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
30e7cd2a51