Dockerize passman for modern environments

Ported the original passman PHP/MySQL application to a Docker-based setup using Apache and MariaDB.
Fixed compatibility issues with modern PHP/MariaDB versions (HTTP header handling and database collation) using minimal, targeted changes.
Preserved the original application logic and structure while ensuring correct execution in a contemporary containerized environment.

passman-dev/php/passman/config.php

@@ -0,0 +1,17 @@
+<?php
+// Database configuration (Docker Compose friendly).
+// NOTE: In Docker, the DB host is the service name (e.g., "db"), not "localhost".
+
+$DB_HOST = getenv('DB_HOST') ?: 'db';
+$DB_USER = getenv('DB_USER') ?: 'root';
+$DB_PASS = getenv('DB_PASS') ?: 'rootpass';
+$DB_NAME = getenv('DB_NAME') ?: 'pwd_mgr';
+
+// Create a DB connection.
+$conn = mysqli_connect($DB_HOST, $DB_USER, $DB_PASS, $DB_NAME);
+
+if (!$conn) {
+    // Fail fast if the DB is not reachable.
+    die("Database connection failed: " . mysqli_connect_error());
+}
+//?>