fix: Strict env enforcement, rock-solid Alpine portal rendering, and Nabeh/Redis test diagnostics

backend/app/Core/Database.php

@@ -7,16 +7,17 @@ use PDOException;
 
 /**
  * PDO Database wrapper using Singleton pattern.
+ * Strict environment variable enforcement (No default fallbacks).
  */
 class Database
 {
     private static ?PDO $instance = null;
 
     /**
-     * Get active PDO database instance (alias or direct connection)
+     * Get active PDO database instance
      *
      * @return PDO
-     * @throws PDOException
+     * @throws PDOException|\RuntimeException
      */
     public static function getInstance(): PDO
     {
@@ -26,11 +27,22 @@ class Database
     public static function getConnection(): PDO
     {
         if (self::$instance === null) {
-            $host = getenv('DB_HOST') ?: '127.0.0.1';
-            $port = getenv('DB_PORT') ?: '3306';
-            $dbName = getenv('DB_DATABASE') ?: 'saqelDB';
-            $username = getenv('DB_USERNAME') ?: 'saqelUser';
-            $password = getenv('DB_PASSWORD') ?: '';
+            $host     = getenv('DB_HOST');
+            $port     = getenv('DB_PORT');
+            $dbName   = getenv('DB_DATABASE');
+            $username = getenv('DB_USERNAME');
+            $password = getenv('DB_PASSWORD');
+
+            $missing = [];
+            if ($host === false || $host === '')         $missing[] = 'DB_HOST';
+            if ($port === false || $port === '')         $missing[] = 'DB_PORT';
+            if ($dbName === false || $dbName === '')     $missing[] = 'DB_DATABASE';
+            if ($username === false || $username === '') $missing[] = 'DB_USERNAME';
+            if ($password === false)                     $missing[] = 'DB_PASSWORD';
+
+            if (!empty($missing)) {
+                throw new \RuntimeException("Database Configuration Error: Missing environment variable(s): " . implode(', ', $missing));
+            }
 
             $dsn = "mysql:host={$host};port={$port};dbname={$dbName};charset=utf8mb4";
 
@@ -43,9 +55,8 @@ class Database
             try {
                 self::$instance = new PDO($dsn, $username, $password, $options);
             } catch (PDOException $e) {
-                // Log the exact error internally but hide sensitive DSN on production
                 error_log("Database Connection Error: " . $e->getMessage());
-                throw new PDOException("Could not connect to the database. Check database settings.");
+                throw new PDOException("Could not connect to MySQL database at {$host}:{$port}/{$dbName}. Error: " . $e->getMessage());
             }
         }
 
@@ -54,10 +65,6 @@ class Database
 
     /**
      * Shorthand execute statement with parameters
-     *
-     * @param string $sql
-     * @param array $params
-     * @return \PDOStatement
      */
     public static function query(string $sql, array $params = []): \PDOStatement
     {