Feature: CSV-Export, UI-Fixes für ToDo-Liste und help.php Absturz behoben

src/articles.php

@@ -127,7 +127,10 @@ $conn->close();
 <div class="card">
     <div class="card-header d-flex justify-content-between align-items-center">
         <h2 class="h4 mb-0"><i class="fas fa-boxes me-2"></i>Artikel im Haushalt</h2>
-        <a href="add_article.php" class="btn btn-sm btn-outline-light"><i class="fas fa-plus me-2"></i>Neuen Artikel hinzufügen</a>
+        <div>
+            <a href="export_articles.php" class="btn btn-sm btn-outline-success me-2"><i class="fas fa-file-export me-2"></i>Export (CSV)</a>
+            <a href="add_article.php" class="btn btn-sm btn-outline-light"><i class="fas fa-plus me-2"></i>Neuen Artikel hinzufügen</a>
+        </div>
     </div>
     <div class="card-body p-0"> 
         <?php echo $message; ?>

src/export_articles.php

@@ -0,0 +1,90 @@
+<?php
+// export_articles.php
+if (session_status() == PHP_SESSION_NONE) {
+    session_start();
+}
+if (!isset($_SESSION['user_id'])) {
+    header("Location: login.php");
+    exit;
+}
+
+require_once 'db_connect.php';
+require_once 'household_actions.php';
+
+$current_user_id = $_SESSION['user_id'];
+$household_member_ids = [$current_user_id];
+$current_user_household_id = get_user_household_id($conn, $current_user_id);
+if ($current_user_household_id) {
+    $household_member_ids = get_household_members($conn, $current_user_household_id);
+}
+
+$placeholders = implode(',', array_fill(0, count($household_member_ids), '?'));
+$types = str_repeat('i', count($household_member_ids));
+
+$sql = "SELECT 
+            a.name AS 'Artikelname', 
+            a.product_designation AS 'Produktbezeichnung',
+            c.name AS 'Kategorie', 
+            m.name AS 'Hersteller',
+            a.weight_grams AS 'Gewicht (g)', 
+            a.quantity_owned AS 'Anzahl', 
+            IF(a.consumable = 1, 'Ja', 'Nein') AS 'Verbrauchsartikel',
+            a.product_url AS 'Produkt-URL',
+            l1.name AS 'Lagerort (Ebene 1)',
+            l2.name AS 'Lagerort (Ebene 2)',
+            u.username AS 'Ersteller'
+        FROM articles a 
+        JOIN users u ON a.user_id = u.id 
+        LEFT JOIN categories c ON a.category_id = c.id 
+        LEFT JOIN manufacturers m ON a.manufacturer_id = m.id
+        LEFT JOIN storage_locations l2 ON a.storage_location_id = l2.id
+        LEFT JOIN storage_locations l1 ON l2.parent_id = l1.id
+        WHERE a.user_id IN ($placeholders) OR a.household_id = ?
+        ORDER BY c.name ASC, a.name ASC";
+
+$stmt = $conn->prepare($sql);
+if ($stmt === false) {
+    die("Datenbankfehler.");
+}
+
+$all_params = array_merge($household_member_ids, [$current_user_household_id]);
+$all_types = $types . 'i';
+$stmt->bind_param($all_types, ...$all_params);
+$stmt->execute();
+$result = $stmt->get_result();
+
+header('Content-Type: text/csv; charset=utf-8');
+header('Content-Disposition: attachment; filename="artikel_export_' . date('Ymd_His') . '.csv"');
+
+$output = fopen('php://output', 'w');
+fprintf($output, chr(0xEF).chr(0xBB).chr(0xBF)); // BOM for Excel
+
+// Output headers
+$headers = [
+    'Artikelname', 'Produktbezeichnung', 'Kategorie', 'Hersteller', 
+    'Gewicht (g)', 'Anzahl im Besitz', 'Verbrauchsartikel', 'Produkt-URL', 
+    'Lagerort (Ebene 1)', 'Lagerort (Ebene 2)', 'Ersteller'
+];
+fputcsv($output, $headers, ';');
+
+// Output rows
+while ($row = $result->fetch_assoc()) {
+    fputcsv($output, [
+        $row['Artikelname'],
+        $row['Produktbezeichnung'],
+        $row['Kategorie'],
+        $row['Hersteller'],
+        $row['Gewicht (g)'],
+        $row['Anzahl'],
+        $row['Verbrauchsartikel'],
+        $row['Produkt-URL'],
+        $row['Lagerort (Ebene 1)'],
+        $row['Lagerort (Ebene 2)'],
+        $row['Ersteller']
+    ], ';');
+}
+
+fclose($output);
+$stmt->close();
+$conn->close();
+?>

src/help.php

@@ -10,6 +10,7 @@ if (!isset($_SESSION['user_id'])) {
     exit;
 }
 
+require_once 'db_connect.php';
 require_once 'header.php';
 ?>
 

src/todo_lists.php

@@ -95,7 +95,7 @@ $active_list_id = isset($_GET['list_id']) ? intval($_GET['list_id']) : (!empty($
                         <h5 class="mb-3"><i class="fas fa-list me-2"></i>Meine Listen</h5>
                         <div class="list-group mb-3 shadow-sm">
                             <?php foreach ($todo_lists as $list): ?>
-                                <a href="?list_id=<?php echo $list['id']; ?>" class="list-group-item list-group-item-action d-flex justify-content-between align-items-center <?php echo $active_list_id == $list['id'] ? 'list-group-item-secondary fw-bold border-start border-4 border-dark' : ''; ?>">
+                                <a href="?list_id=<?php echo $list['id']; ?>" class="list-group-item list-group-item-action d-flex justify-content-between align-items-center <?php echo $active_list_id == $list['id'] ? 'bg-success text-white fw-bold' : ''; ?>">
                                     <?php echo htmlspecialchars($list['name']); ?>
                                     <form method="post" style="display:inline;" onsubmit="return confirm('Liste wirklich löschen?');">
                                         <input type="hidden" name="list_id" value="<?php echo $list['id']; ?>">