test(refactor): switch to bashunit and start fleshing out a new test suite

tests/bootstrap.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+set -euo pipefail
+# Place your common test setup here
+
+# Resolve the project root directory
+_test_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+_root_dir="$(cd "${_test_dir}/.." && pwd)"
+
+# Set TMUXIFIER so libexec commands can find lib/util.sh
+export TMUXIFIER="${_root_dir}"
+
+# Add libexec to PATH so tmuxifier commands are available
+export PATH="${_root_dir}/libexec:${PATH}"