feat: add payment tracking for orders

- Add payment method selection (PayPal/Bar) to order form
- Store payment_method and payment_status in database
- Add payment status badges in admin orders view
- Add "mark as paid" functionality for admins
- PayPal account configurable via PAYPAL_ACCOUNT env variable
- Frontend loads PayPal account dynamically from /wawi/config endpoint
- Update email notifications to include payment method

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

wawi/templates/orders.html

@@ -20,6 +20,8 @@
           <th>Artikel</th>
           <th>Größe</th>
           <th>Menge</th>
+          <th>Zahlungsart</th>
+          <th>Zahlung</th>
           <th>Notiz</th>
           <th>Status</th>
           <th class="actions">Aktion</th>
@@ -35,6 +37,16 @@
             <td>{{ o.artikel }}</td>
             <td>{{ o.groesse }}</td>
             <td>{{ o.menge }}</td>
+            <td>
+              {% if o.payment_method == "paypal" %}PayPal
+              {% else %}Bar
+              {% endif %}
+            </td>
+            <td>
+              {% if o.payment_status == "paid" %}<span class="badge success">Bezahlt</span>
+              {% else %}<span class="badge warning">Unbezahlt</span>
+              {% endif %}
+            </td>
             <td>{{ o.notiz or "–" }}</td>
             <td>
               {% if o.canceled %}Storniert
@@ -48,6 +60,12 @@
                   <input type="hidden" name="csrf_token" value="{{ csrf_token() }}"/>
                   <button class="btn small" type="submit">Erledigt</button>
                 </form>
+                {% if o.payment_status != "paid" %}
+                  <form method="post" action="{{ url_for('bp.mark_paid', order_id=o.id) }}" onsubmit="return confirm('Als bezahlt markieren?');">
+                    <input type="hidden" name="csrf_token" value="{{ csrf_token() }}"/>
+                    <button class="btn small success" type="submit">Bezahlt</button>
+                  </form>
+                {% endif %}
                 <form method="post" action="{{ url_for('bp.cancel_order', order_id=o.id) }}" onsubmit="return confirm('Bestellung wirklich stornieren?');">
                   <input type="hidden" name="csrf_token" value="{{ csrf_token() }}"/>
                   <button class="btn small danger" type="submit">Stornieren</button>
@@ -58,12 +76,14 @@
             </td>
           </tr>
           <tr class="order-history">
-            <td colspan="10">
+            <td colspan="12">
               <details class="inline-details">
                 <summary>Historie</summary>
                 <div class="history-grid">
                   <div><strong>Abgeschlossen von:</strong> {{ o.completed_by or "–" }}</div>
                   <div><strong>Abgeschlossen am:</strong> {{ o.completed_at or "–" }}</div>
+                  <div><strong>Bezahlt markiert von:</strong> {{ o.paid_by or "–" }}</div>
+                  <div><strong>Bezahlt markiert am:</strong> {{ o.paid_at or "–" }}</div>
                   <div><strong>Storniert von:</strong> {{ o.canceled_by or "–" }}</div>
                   <div><strong>Storniert am:</strong> {{ o.canceled_at or "–" }}</div>
                 </div>
@@ -72,7 +92,7 @@
           </tr>
         {% else %}
           <tr>
-            <td colspan="10" class="empty">Keine Bestellungen.</td>
+            <td colspan="12" class="empty">Keine Bestellungen.</td>
           </tr>
         {% endfor %}
       </tbody>