AgyIntegration.build_exec_args returned [exe, '--print', prompt] without
calling _apply_extra_args_env_var(), so the documented per-integration
extra-args env hook was silently dropped for agy — same class as the
cursor-agent fix#3265. Append the hook after the positional prompt,
matching the devin integration's shape. agy still ignores model/output
as before.
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>