Add pdm package manager support

PDM is a modern Python package manager using pyproject.toml (PEP 621).
Uses the same MITM-only proxy approach as poetry/uv/pipx — all malware
detection and minimum package age enforcement happens at the proxy layer
by intercepting PyPI requests.

packages/safe-chain/bin/aikido-pdm.js

@@ -0,0 +1,13 @@
+#!/usr/bin/env node
+
+import { main } from "../src/main.js";
+import { initializePackageManager } from "../src/packagemanager/currentPackageManager.js";
+import { setEcoSystem, ECOSYSTEM_PY } from "../src/config/settings.js";
+
+setEcoSystem(ECOSYSTEM_PY);
+initializePackageManager("pdm");
+
+(async () => {
+  var exitCode = await main(process.argv.slice(2));
+  process.exit(exitCode);
+})();