refactor(model): rename Postcard.country -> country_to for clear semantics - country_from: origin country (where postcard was sent from) - country_to: destination country (where postcard was sent to) - Profile.country remains as user's home country - Updated all routes, schemas, templates, and API endpoints

app/templates/dashboard.html

@@ -118,8 +118,10 @@ new Chart(document.getElementById('chart-received'), {
                     <span class="badge badge-{{ pc.status }}">{{ {'sent':'已寄出','delivered':'已送达','received':'已收到'}.get(pc.status) if user.language=='zh' else {'sent':'Sent','delivered':'Delivered','received':'Received'}.get(pc.status) }}</span>
                 </div>
                 <div class="recent-meta">
+                    {% if pc.country_from and pc.country_to %}<span>{{ pc.country_from|flag }} {{ pc.country_from }} → {{ pc.country_to|flag }} {{ pc.country_to }}</span>
+                    {% elif pc.country_to %}<span>{{ pc.country_to|flag }} {{ pc.country_to }}</span>
+                    {% endif %}
                     {% if pc.status in ('sent','delivered') %}
-                    <span>{{ pc.country|flag }} {{ pc.country or '' }}</span>
                     <span>→ {{ pc.recipient_name or '-' }}</span>
                     {% else %}
                     <span>← {{ pc.sender_name or '-' }}</span>