8fc0610a53
The bash tool is named "bash" and described as executing bash commands, but was using sh on Unix. On many distros (Ubuntu, Debian, Alpine, etc.), /bin/sh is a POSIX-only shell that doesn't support bash syntax like [[ ]], arrays, or here-strings. This caused the LLM to write bash syntax that failed, wasting tokens on rewrites. Now prefers /bin/bash on Unix, falling back to sh only if bash isn't found.