feat: universal reorder grip handles and compact UI density

- Add generic move_in_order() to BaseRepository for reorder support
- Add reusable reorder_arrows.html partial with grip dot handles
- Add reorder routes to all 9 list routers (tasks, notes, links, contacts, meetings, decisions, appointments, lists, focus)
- Compact row padding (6px 12px, gap 8px) on .list-row and .focus-item
- Reduce font size to 0.80rem on row titles, sidebar nav, domain tree

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

templates/appointments.html

@@ -30,6 +30,9 @@
         {% endif %}
 
         <div class="list-row">
+            {% with reorder_url="/appointments/reorder", item_id=appt.id %}
+            {% include 'partials/reorder_arrows.html' %}
+            {% endwith %}
             <div style="flex-shrink: 0; min-width: 60px;">
                 {% if appt.all_day %}
                     <span class="status-badge status-active" style="font-size: 0.72rem;">All Day</span>