[dmazhukov]

Refs #3663 (the -h part; -l/-m/-t are already long-only on develop).

Summary

rtk grep -h PATTERN FILES still prints rtk's usage text on develop: clap's auto help flag captures -h before search.rs, which already reads it as grep's --no-filename (and as help for rg only), ever sees it. Agents piping grep -ho ... | sort | uniq -c get the help screen and fall back to rtk proxy grep.

This disables clap's help flag on the Grep subcommand (same precedent as Psql). --help still reaches the engine through search.rs. Rebased on current develop: the filename handling from the first version is dropped, since develop now does it in search.rs.

Test plan

• cargo fmt --all && cargo clippy --all-targets && cargo test
• dash_h_is_no_filename_not_help in tests/grep_faithful_format_test.rs pins -h, -ho and -H against real grep byte for byte

Side note, not addressed here: with -h -H together develop follows GNU grep (last flag wins, filename shown), while BSD grep on macOS lets -h win regardless of order.

[CLAassistant]

All committers have signed the CLA.

[KuSh]

Thanks for this, and for pinning the -ho cluster. I'm closing it as superseded by #4348, which releases clap's help flag on every wrapper subcommand. On its head, rtk grep -h, -ho and -hn match grep byte for byte, and --help still reaches grep.