fix(toolkit): set version 0.2.1 and private:true to prevent premature publish (#67)

The release workflow's Changesets action publishes any package whose local
version hasn't been published on npm, even without a changeset. This caused
@ocpp-debugkit/toolkit@0.2.0 to be auto-published when PR #55 merged with
only Phase 0 consolidation code.

Fix: set version to 0.2.1 (next available) and private:true to prevent any
auto-publishing. private:true will be removed in the release issue (#66)
when all v0.2.0 features are complete and we're ready to publish.

Author: sepehr-safari

packages/toolkit/package.json

@@ -1,10 +1,11 @@
 {
   "name": "@ocpp-debugkit/toolkit",
-  "version": "0.2.0",
+  "version": "0.2.1",
   "description": "Open-source DevTools for debugging OCPP charging sessions — parser, normalizer, timeline, failure detection, scenarios, replay, reports, CLI, and React components.",
   "license": "Apache-2.0",
   "type": "module",
   "sideEffects": false,
+  "private": true,
   "main": "./dist/index.js",
   "module": "./dist/index.js",
   "types": "./dist/index.d.ts",