Fix: eagerload series.sets i admin og API (MissingGreenlet i async mode)

backend/app/templates/card_detail.html

@@ -0,0 +1,56 @@
+{% extends "base.html" %}
+{% block title %}{{ card.full_code }} — {{ card.name }}{% endblock %}
+{% block content %}
+<a href="/sets/{{ card.set.code }}" style="color:var(--text-muted);text-decoration:none;font-size:0.9rem;">
+    &larr; {{ card.set.serie.name }} — {{ card.set.name }}
+</a>
+
+<div style="display:flex;gap:32px;margin-top:20px;flex-wrap:wrap;">
+    <div style="flex:0 0 auto;max-width:400px;">
+        {% if card.image_url %}
+        <img src="{{ card.image_url }}" alt="{{ card.name }}"
+             style="width:100%;border-radius:12px;border:2px solid var(--border);box-shadow:0 4px 20px var(--shadow);">
+        {% else %}
+        <div class="card" style="width:320px;height:440px;display:flex;align-items:center;justify-content:center;
+                    text-align:center;color:var(--text-muted);">
+            <div>
+                <p style="font-size:3rem;margin-bottom:12px;">🃏</p>
+                <p>Intet billede tilgængeligt</p>
+            </div>
+        </div>
+        {% endif %}
+    </div>
+
+    <div style="flex:1;min-width:200px;">
+        <h1 style="margin-bottom:4px;">
+            <span class="tag">{{ card.full_code }}</span>
+        </h1>
+        <h2 style="font-size:1.8rem;margin:0 0 20px 0;color:var(--text);">{{ card.name }}</h2>
+
+        <div class="card" style="margin-bottom:16px;">
+            <table style="margin:0;">
+                <tr>
+                    <td style="font-weight:600;width:100px;">Sæt</td>
+                    <td>
+                        <a href="/sets/{{ card.set.code }}" style="color:var(--text);">
+                            {{ card.set.code }} — {{ card.set.name }}
+                        </a>
+                    </td>
+                </tr>
+                <tr>
+                    <td style="font-weight:600;">Serie</td>
+                    <td>
+                        <a href="/series/{{ card.set.serie.name|urlencode }}" style="color:var(--text);">
+                            {{ card.set.serie.name }}
+                        </a>
+                    </td>
+                </tr>
+                <tr>
+                    <td style="font-weight:600;">Nummer</td>
+                    <td>{{ card.number }}</td>
+                </tr>
+            </table>
+        </div>
+    </div>
+</div>
+{% endblock %}