When --random is used, the runner writes the shuffled spec list to $SHELLSPEC_INFILE, which defaults to the relative path file. This drops a stray file named file into the working/project directory, silently overwrites any existing ./file, and is never cleaned up, unlike every other internal scratch file.

Reproduce this issue with:

mkdir /tmp/shellspec_test && cd /tmp/shellspec_test
shellspec --init
echo 'IMPORTANT - do not delete' > file

shellspec --random specfiles      # also: --random examples

cat file        # -> overwritten with the spec list
ls file         # -> still present after shellspec exits

Along with this fix:

• Added spec/random_no_stray_file_spec.sh: a regression spec parameterized over both --random specfiles and --random examples (the two paths through the write). It runs the binary in an isolated project and asserts the working directory gains no unexpected entries. Because the self-test suite runs under --sandbox, which makes PATH read-only, the nested binary is launched via a fresh sh -c with PATH restored from $SHELLSPEC_POSIX_PATH.
• Also added a CHANGELOG.md entry under [Unreleased].