chore: charge .env via --env-file dans dev:server et start (Node 22+)

L'app lit process.env sans dotenv ; les scripts npm ne fournissaient pas
SU_MASTER_KEY. Ajoute --env-file=.env pour que pnpm dev / pnpm start
fonctionnent directement.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

package.json

@@ -8,10 +8,10 @@
   },
   "scripts": {
     "dev": "pnpm run dev:server & pnpm run dev:client",
-    "dev:server": "tsx watch server/index.ts",
+    "dev:server": "tsx watch --env-file=.env server/index.ts",
     "dev:client": "vite",
     "build": "vite build && tsup",
-    "start": "node dist/index.js",
+    "start": "node --env-file=.env dist/index.js",
     "test": "vitest run",
     "check": "tsc --noEmit",
     "db:generate": "drizzle-kit generate",