Tighten Node engine pin, bump pnpm, add pnpm hygiene to gitignore

Align engines.node with the .nvmrc 24.2.0 pin so npm/pnpm warn on
mismatched local toolchains, move packageManager to the current
pnpm 9.15.3 patch, and ignore pnpm's local store and debug log so
stray artefacts never get committed.

.gitignore

@@ -13,6 +13,8 @@ dist/
 ClientApp/dist/
 ClientApp/coverage/
 ClientApp/.storybook-out/
+.pnpm-store/
+.pnpm-debug.log
 
 # Logs
 *.log

package.json

@@ -6,10 +6,10 @@
   "license": "UNLICENSED",
   "type": "module",
   "engines": {
-    "node": ">=24.0.0",
+    "node": ">=24.2.0",
     "pnpm": ">=9.0.0"
   },
-  "packageManager": "pnpm@9.15.0",
+  "packageManager": "pnpm@9.15.3",
   "scripts": {
     "dev": "echo \"dev script wired in 1A-2\" && exit 1",
     "build:standalone": "echo \"build:standalone wired in 1A-2\" && exit 1",