chore: enforce zero-warning toolchain

- Enable noUnusedLocals/noUnusedParameters in tsconfig (unused code = error)
- Remove unused React import in scroll-area (caught by strict unused checks)
- Pin NODE_ENV=development for dev script (box shell leaks NODE_ENV=production,
  which made next dev emit a non-standard-env warning)

components/ui/scroll-area.tsx

@@ -1,6 +1,5 @@
 "use client";
 
-import * as React from "react";
 import { ScrollArea as ScrollAreaPrimitive } from "@base-ui/react/scroll-area";
 import { cn } from "cn";
 

package.json

@@ -3,7 +3,7 @@
   "version": "0.1.0",
   "private": true,
   "scripts": {
-    "dev": "next dev",
+    "dev": "NODE_ENV=development next dev",
     "build": "next build",
     "start": "next start",
     "lint": "eslint",

tsconfig.json

@@ -5,6 +5,8 @@
     "allowJs": true,
     "skipLibCheck": true,
     "strict": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
     "noEmit": true,
     "esModuleInterop": true,
     "module": "esnext",