new system prototype

lib/response.php

@@ -0,0 +1,24 @@
+<?php
+
+function json_success(mixed $data, int $status = 200): never {
+    http_response_code($status);
+    header('Content-Type: application/json; charset=UTF-8');
+    echo json_encode(["ok" => true, "data" => $data]);
+    exit;
+}
+
+function json_error(string $code, string $message, int $status = 400): never {
+    http_response_code($status);
+    header('Content-Type: application/json; charset=UTF-8');
+    echo json_encode(["ok" => false, "error" => ["code" => $code, "message" => $message]]);
+    exit;
+}
+
+function read_json_body(): array {
+    $raw = file_get_contents('php://input');
+    $data = json_decode($raw, true);
+    if (!is_array($data)) {
+        json_error('INVALID_BODY', 'Request body must be valid JSON', 400);
+    }
+    return $data;
+}