The OpenCode /ponytail-help card listed 5 commands, omitting /ponytail-gain,
while the Claude commands/*.toml card lists all 6. An OpenCode user wouldn't
see that ponytail-gain exists. Add it so both help surfaces agree.
Ships the previously-missing /ponytail-help adapter files (commands/ponytail-help.toml, .opencode/command/ponytail-help.md) and adds tests/commands.test.js, a parity guard asserting every pi-registered command has both adapter files. Thanks @hooni0918.
DietrichGebert