refactor: migrate from ESLint to Biome and extract SQL queries to data.ts

- Replace ESLint with Biome for linting and formatting
- Configure Biome with tabs, double quotes, and organized imports
- Move all SQL/Drizzle queries from page.tsx files to data.ts files
- Create new data.ts files for: ajustes, dashboard, relatorios/categorias
- Update existing data.ts files: extrato, fatura (add lancamentos queries)
- Remove all drizzle-orm imports from page.tsx files
- Update README.md with new tooling info

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/(auth)/signup/page.tsx

@@ -1,11 +1,11 @@
 import { SignupForm } from "@/components/auth/signup-form";
 
 export default function Page() {
-  return (
-    <div className="flex min-h-svh flex-col items-center justify-center p-6 md:p-10">
-      <div className="w-full max-w-sm md:max-w-4xl">
-        <SignupForm />
-      </div>
-    </div>
-  );
+	return (
+		<div className="flex min-h-svh flex-col items-center justify-center p-6 md:p-10">
+			<div className="w-full max-w-sm md:max-w-4xl">
+				<SignupForm />
+			</div>
+		</div>
+	);
 }