Refactor PolicyEngine to Core Package (#12325)

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

package-lock.json

@@ -17355,6 +17355,7 @@
         "@google-cloud/opentelemetry-cloud-monitoring-exporter": "^0.21.0",
         "@google-cloud/opentelemetry-cloud-trace-exporter": "^3.0.0",
         "@google/genai": "1.16.0",
+        "@iarna/toml": "^2.2.5",
         "@joshua.litt/get-ripgrep": "^0.0.3",
         "@modelcontextprotocol/sdk": "^1.11.0",
         "@opentelemetry/api": "^1.9.0",
@@ -17396,7 +17397,8 @@
         "tree-sitter-bash": "^0.25.0",
         "undici": "^7.10.0",
         "web-tree-sitter": "^0.25.10",
-        "ws": "^8.18.0"
+        "ws": "^8.18.0",
+        "zod": "^3.25.76"
       },
       "devDependencies": {
         "@google/gemini-cli-test-utils": "file:../test-utils",