v1.8.0 — add plan2code-metrics recursive self-improvement toolchain

New package for contributors to collect, aggregate, analyze, and improve
workflow prompts based on real project data. Includes unit tests (vitest),
installer integration, and loop/finalize hints.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "plan2code",
-  "version": "1.7.0",
+  "version": "1.8.0",
   "private": true,
   "bin": {
     "plan2code": "./install.js"