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/api/saves.php

@@ -0,0 +1,44 @@
+<?php
+/**
+ * API: Spielstaende speichern/laden
+ * GET  /api/saves?key=klimawaechter-save  → Spielstand laden
+ * POST /api/saves {key, data, version}     → Spielstand speichern
+ */
+
+header('Content-Type: application/json; charset=utf-8');
+
+$method = $_SERVER['REQUEST_METHOD'];
+$db = Database::get();
+
+if ($method === 'GET') {
+    $sessionId = Session::studentId();
+    if (!$sessionId) {
+        Response::json(['data' => null]);
+    }
+    $key = $_GET['key'] ?? '';
+    if (!$key) Response::error('key fehlt');
+
+    $row = $db->fetchOne(
+        'SELECT save_data, save_version FROM game_saves WHERE session_id = ? AND save_key = ?',
+        [$sessionId, $key]
+    );
+    Response::json(['data' => $row ? $row['save_data'] : null, 'version' => $row ? (int)$row['save_version'] : null]);
+}
+
+if ($method === 'POST') {
+    $sessionId = Session::requireStudent();
+    $body = json_decode(file_get_contents('php://input'), true);
+    if (!$body || !isset($body['key']) || !isset($body['data'])) {
+        Response::error('key und data erforderlich');
+    }
+
+    $db->execute(
+        'INSERT INTO game_saves (session_id, save_key, save_data, save_version)
+         VALUES (?, ?, ?, ?)
+         ON DUPLICATE KEY UPDATE save_data = VALUES(save_data), save_version = VALUES(save_version)',
+        [$sessionId, $body['key'], $body['data'], $body['version'] ?? 2]
+    );
+    Response::ok();
+}
+
+Response::error('Methode nicht erlaubt', 405);