chore: add Biome for formatting and linting (#116)

- Add Biome as formatter and linter (replaces Prettier)
- Configure Husky + lint-staged for pre-commit hooks
- Add VS Code settings for format on save
- Ignore components/ui/ (shadcn generated code)
- Remove semicolons, use 4-space indent
- Reformat all files to new style

app/api/config/route.ts

@@ -1,9 +1,12 @@
-import { NextResponse } from "next/server";
+import { NextResponse } from "next/server"
 
 export async function GET() {
-  const accessCodes = process.env.ACCESS_CODE_LIST?.split(',').map(code => code.trim()).filter(Boolean) || [];
+    const accessCodes =
+        process.env.ACCESS_CODE_LIST?.split(",")
+            .map((code) => code.trim())
+            .filter(Boolean) || []
 
-  return NextResponse.json({
-    accessCodeRequired: accessCodes.length > 0,
-  });
+    return NextResponse.json({
+        accessCodeRequired: accessCodes.length > 0,
+    })
 }