feat: implement Prisma singleton for memory efficiency and add memory monitoring options

package.json

@@ -5,7 +5,11 @@
   "main": "src/main.ts",
   "scripts": {
     "start": "npx tsx watch src/main.ts",
-    "dev": "npx tsx watch src/main.ts"
+    "dev": "npx tsx watch src/main.ts",
+    "dev:light": "CACHE_MESSAGES_LIMIT=25 CACHE_MEMBERS_LIMIT=50 SWEEP_MESSAGES_LIFETIME_SECONDS=600 SWEEP_MESSAGES_INTERVAL_SECONDS=240 npx tsx watch --clear-screen=false src/main.ts",
+    "dev:mem": "MEMORY_LOG_INTERVAL_SECONDS=120 npx tsx watch src/main.ts",
+    "start:prod": "NODE_ENV=production NODE_OPTIONS=--max-old-space-size=384 npx tsx src/main.ts",
+    "typecheck": "tsc --noEmit"
   },
   "keywords": [ ],
   "author": "",