(chore): initial MVP release

core/connection.php

@@ -0,0 +1,56 @@
+<?php
+// core/connection.php
+declare(strict_types=1);
+
+require __DIR__ . '/vendor/autoload.php';
+
+use Dotenv\Dotenv;
+
+// Load .env from project root
+$dotenv = Dotenv::createImmutable(dirname(__DIR__));
+$dotenv->load();
+
+date_default_timezone_set('Asia/Kolkata');
+
+function env(string $key, ?string $default = null): ?string
+{
+    return $_ENV[$key] ?? $_SERVER[$key] ?? $default;
+}
+
+$debug = filter_var(env('APP_DEBUG', 'false'), FILTER_VALIDATE_BOOLEAN);
+
+ini_set('display_errors', $debug ? '1' : '0');
+ini_set('display_startup_errors', $debug ? '1' : '0');
+error_reporting(
+    $debug ? E_ALL : (E_ALL & ~E_NOTICE & ~E_DEPRECATED & ~E_STRICT)
+);
+
+try {
+    $pdo = new PDO(
+        sprintf(
+            'mysql:host=%s;dbname=%s;charset=utf8mb4',
+            env('DB_HOST', '127.0.0.1'),
+            env('DB_NAME', 'isdowndetectordown')
+        ),
+        env('DB_USER', 'root'),
+        env('DB_PASS', ''),
+        [
+            PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
+            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
+            PDO::ATTR_EMULATE_PREPARES   => false,
+        ]
+    );
+} catch (PDOException $e) {
+    http_response_code(500);
+    echo 'DB connection failed';
+    if ($debug) {
+        echo ': ' . htmlspecialchars($e->getMessage(), ENT_QUOTES, 'UTF-8');
+    }
+    exit;
+}
+
+function db(): PDO
+{
+    global $pdo;
+    return $pdo;
+}