Stand 2026-04-13: PHP/MySQL Infrastruktur, Flussmanagement, Stadt-Prototyp

- PHP/MySQL Backend (XAMPP + Produktionsserver)
- Front-Controller, API-Endpunkte, Session-Management
- Flussmanagement-Simulation (Echtzeit, Punkt-basierter Fluss)
- Stadt & Raumplanung (Prototyp, Top-Down Kachelsystem)
- Klimawaechter 3D: Deiche kleiner, Baeume kippen, Budget angepasst
- persistence.ts: Dualer Speicher (localStorage + Server-API)
- 6 Unit-Test-Dateien fuer bestehende Simulationen

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

App/php/config/db.php

@@ -0,0 +1,19 @@
+<?php
+/**
+ * GeoGraSim — Database Connection (PDO)
+ */
+
+require_once __DIR__ . '/app.php';
+
+function getDB(): PDO {
+    static $pdo = null;
+    if ($pdo === null) {
+        $dsn = sprintf('mysql:host=%s;port=%s;dbname=%s;charset=utf8mb4', DB_HOST, DB_PORT, DB_NAME);
+        $pdo = new PDO($dsn, DB_USER, DB_PASS, [
+            PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
+            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
+            PDO::ATTR_EMULATE_PREPARES   => false,
+        ]);
+    }
+    return $pdo;
+}