Implement Schengen Area Compliance Report

How many close am I to 90 days in the last 180.

Fixes #193.

templates/trip_page.html

@@ -117,6 +117,25 @@
     {% if delta %}
       <div>How long until trip: {{ delta }}</div>
     {% endif %}
+    
+    {% if trip.schengen_compliance %}
+      <div class="mt-3">
+        <strong>Schengen Compliance:</strong>
+        {% if trip.schengen_compliance.is_compliant %}
+          <span class="badge bg-success">✅ Compliant</span>
+        {% else %}
+          <span class="badge bg-danger">❌ Non-compliant</span>
+        {% endif %}
+        <div class="text-muted small">
+          {{ trip.schengen_compliance.total_days_used }}/90 days used
+          {% if trip.schengen_compliance.is_compliant %}
+            ({{ trip.schengen_compliance.days_remaining }} remaining)
+          {% else %}
+            ({{ trip.schengen_compliance.days_over_limit }} over limit)
+          {% endif %}
+        </div>
+      </div>
+    {% endif %}
     </div>
 
     {% for item in trip.conferences %}