Auto-create apps/cms/.env from .env.example if missing

pnpm dev was failing with "App keys are required" for anyone whose
apps/cms/.env didn't already exist (it's gitignored, so this hits
every fresh clone, not just a one-off). predev/predevelop now copy
.env.example to .env automatically when it's absent, so `pnpm dev`
and `pnpm --filter cms develop` both just work without a manual setup
step.

apps/cms/package.json

@@ -4,6 +4,8 @@
   "private": true,
   "description": "A Strapi application",
   "scripts": {
+    "predev": "test -f .env || cp .env.example .env",
+    "predevelop": "test -f .env || cp .env.example .env",
     "build": "strapi build",
     "console": "strapi console",
     "deploy": "strapi deploy",