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.
Build outputs to dist/modes/interactive/theme/*.json but workflow
expected dist/theme/*.json. The copy-binary-assets script creates
dist/theme/ but CI never invokes it.
Fixes v0.18.0 release failure:
https://github.com/badlogic/pi-mono/actions/runs/20082833642
Daniel Nouri