refactor: extract signals filter builder, add ESLint 10 config, fix low-hanging issues

web/app/api/alerts/route.ts

@@ -1,6 +1,7 @@
-import { NextRequest, NextResponse } from 'next/server';
-import pool from '@/lib/db';
+import { type NextRequest, NextResponse } from 'next/server';
+
 import { withAuth } from '@/lib/apiHelpers';
+import pool from '@/lib/db';
 
 export const GET = withAuth(async () => {
   const result = await pool.query('SELECT * FROM alerts ORDER BY created_at DESC');