feat: Implement floors, locations, and racks management

- Added list, edit, and save functionalities for floors, locations, and racks.
- Enhanced UI with search and filter options for better usability.
- Implemented SVG upload for floor plans in the floors module.
- Added validation for required fields in the save processes.
- Improved navigation in the header to reflect new modules.
- Styled forms and tables for a consistent look and feel across modules.

app/modules/buildings/save.php

@@ -0,0 +1,49 @@
+<?php
+/**
+ * app/modules/buildings/save.php
+ */
+
+if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
+    header('Location: ?module=buildings&action=list');
+    exit;
+}
+
+$buildingId = (int)($_POST['id'] ?? 0);
+$name = trim($_POST['name'] ?? '');
+$locationId = (int)($_POST['location_id'] ?? 0);
+$comment = trim($_POST['comment'] ?? '');
+
+$errors = [];
+
+if (empty($name)) {
+    $errors[] = "Name ist erforderlich";
+}
+
+if ($locationId <= 0) {
+    $errors[] = "Standort ist erforderlich";
+}
+
+if (!empty($errors)) {
+    $_SESSION['error'] = implode(', ', $errors);
+    $redirectUrl = $buildingId ? "?module=buildings&action=edit&id=$buildingId" : "?module=buildings&action=edit";
+    header("Location: $redirectUrl");
+    exit;
+}
+
+if ($buildingId > 0) {
+    $sql->set(
+        "UPDATE buildings SET name = ?, location_id = ?, comment = ? WHERE id = ?",
+        "sisi",
+        [$name, $locationId, $comment, $buildingId]
+    );
+} else {
+    $sql->set(
+        "INSERT INTO buildings (name, location_id, comment) VALUES (?, ?, ?)",
+        "sis",
+        [$name, $locationId, $comment]
+    );
+}
+
+$_SESSION['success'] = "Gebäude gespeichert";
+header('Location: ?module=buildings&action=list');
+exit;