Add shared catalogue header and tab strip

app/templates/admin/labels/_nav.html

@@ -0,0 +1,35 @@
+{# Shared catalogue header: title bar, tabs, breadcrumb.
+   Set `section` and `crumbs` before including.
+   Created by: Jess Rogerson (yelling commands at Claude.AI) #}
+<div class="bl-bar">
+    <div>
+        <h1><i class="bi bi-tags"></i> Parts Catalogue &amp; Labels</h1>
+        <div class="bl-sub">{{ bar_sub|default('Drawer and bag labelling') }}</div>
+    </div>
+    <div class="d-flex gap-1">
+        <a href="{{ url_for('labels.new_label') }}" class="bl-btn bl-btn-go">
+            <i class="bi bi-plus-lg"></i> New Label
+        </a>
+        <a href="{{ url_for('admin.dashboard') }}" class="bl-btn">Admin</a>
+    </div>
+</div>
+
+<div class="bl-tabs">
+    <a href="{{ url_for('labels.index') }}"
+       class="{% if section == 'labels' %}active{% endif %}">My Labels</a>
+    <a href="{{ url_for('catalog.index') }}"
+       class="{% if section == 'catalog' %}active{% endif %}">Part Catalogue</a>
+    <a href="{{ url_for('labels.categories') }}"
+       class="{% if section == 'categories' %}active{% endif %}">Categories</a>
+    <a href="{{ url_for('labels.settings') }}"
+       class="{% if section == 'settings' %}active{% endif %}">Settings</a>
+</div>
+
+<div class="bl-crumb">
+    <a href="{{ url_for('labels.index') }}">Catalogue</a>
+    {% for crumb in crumbs|default([]) %}
+        <span class="sep">&rsaquo;</span>
+        {% if crumb.url %}<a href="{{ crumb.url }}">{{ crumb.name }}</a>
+        {% else %}{{ crumb.name }}{% endif %}
+    {% endfor %}
+</div>