feat(db): setup drizzle config, client and package scripts

- Add drizzle.config.ts with PostgreSQL dialect configuration
- Create lib/db/index.ts with Drizzle ORM client and pg Pool
- Add db:generate, db:migrate, db:studio, db:push scripts to package.json

Part of Chunk 1: Drizzle Config & DB Client setup

package.json

@@ -6,10 +6,15 @@
     "dev": "next dev --experimental-https",
     "build": "next build",
     "start": "next start",
-    "lint": "eslint"
+    "lint": "eslint",
+    "db:generate": "drizzle-kit generate",
+    "db:migrate": "drizzle-kit migrate",
+    "db:studio": "drizzle-kit studio",
+    "db:push": "drizzle-kit push"
   },
   "dependencies": {
     "@aws-sdk/client-s3": "^3.1036.0",
+    "@better-auth/drizzle-adapter": "^1.6.9",
     "@elysia/eden": "^1.4.10",
     "@tiptap/core": "^3.22.4",
     "@tiptap/pm": "^3.22.4",
@@ -18,6 +23,7 @@
     "better-auth": "^1.6.9",
     "dotenv": "^17.4.2",
     "drizzle-orm": "^0.45.2",
+    "echarts": "^6.0.0",
     "elysia": "^1.4.28",
     "lucide-react": "^1.11.0",
     "motion": "^12.38.0",