test: add missing implementation-plan test targets

tests/bun_test_test/cache_miss_shape.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+rule_file="$1"
+
+grep -Eq 'files = \[bun_bin\] \+ ctx\.files\.srcs \+ ctx\.files\.data' "${rule_file}"
+grep -Eq '"srcs": attr\.label_list\(' "${rule_file}"