refactor: migrate authentication system and update Drizzle schema.

package.json

@@ -5,7 +5,7 @@
   "type": "module",
   "scripts": {
     "build": "next build",
-    "check": "next lint && tsc --noEmit",
+    "check": "eslint . && tsc --noEmit",
     "db:generate": "drizzle-kit generate",
     "db:migrate": "drizzle-kit migrate",
     "db:push": "drizzle-kit push",
@@ -17,14 +17,13 @@
     "dev": "next dev --turbo",
     "format:check": "prettier --check \"**/*.{ts,tsx,js,jsx,mdx}\" --cache",
     "format:write": "prettier --write \"**/*.{ts,tsx,js,jsx,mdx}\" --cache",
-    "lint": "next lint",
-    "lint:fix": "next lint --fix",
+    "lint": "eslint .",
+    "lint:fix": "eslint --fix .",
     "preview": "next build && next start",
     "start": "next start",
     "typecheck": "tsc --noEmit"
   },
   "dependencies": {
-    "@auth/drizzle-adapter": "^1.11.1",
     "@dnd-kit/core": "^6.3.1",
     "@dnd-kit/sortable": "^10.0.0",
     "@dnd-kit/utilities": "^3.2.2",
@@ -58,6 +57,7 @@
     "@trpc/server": "^11.7.2",
     "@vercel/analytics": "^1.5.0",
     "bcryptjs": "^3.0.3",
+    "better-auth": "^1.4.3",
     "chrono-node": "^2.9.0",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
@@ -66,8 +66,7 @@
     "file-saver": "^2.0.5",
     "framer-motion": "^12.23.24",
     "lucide-react": "^0.525.0",
-    "next": "^15.5.6",
-    "next-auth": "5.0.0-beta.25",
+    "next": "^16.0.5",
     "pg": "^8.16.3",
     "react": "^19.2.0",
     "react-day-picker": "^9.11.2",
@@ -82,7 +81,6 @@
     "zod": "^3.25.76"
   },
   "devDependencies": {
-    "@eslint/eslintrc": "^3.3.1",
     "@tailwindcss/postcss": "^4.1.17",
     "@types/bcryptjs": "^2.4.6",
     "@types/file-saver": "^2.0.7",
@@ -94,7 +92,7 @@
     "dotenv": "^17.2.3",
     "drizzle-kit": "^0.30.6",
     "eslint": "^9.39.1",
-    "eslint-config-next": "^15.5.6",
+    "eslint-config-next": "^16.0.5",
     "eslint-plugin-drizzle": "^0.2.3",
     "postcss": "^8.5.6",
     "prettier": "^3.6.2",
@@ -115,4 +113,4 @@
     "sharp",
     "unrs-resolver"
   ]
-}
+}