test: add missing implementation-plan test targets

Co-authored-by: Eriyc <50216491+Eriyc@users.noreply.github.com>

tests/bun_test_test/failing_suite_shape.sh

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+build_file="$1"
+
+grep -Eq 'name = "failing_suite"' "${build_file}"
+if grep -Eq 'tags = \["manual"\]' "${build_file}"; then
+  echo "failing_suite must be automated (not manual-only)" >&2
+  exit 1
+fi