Add MOT/insurance renewal hints, table service card, and favicon

- Renewal tracking: compute due/overdue status from the most recent
  mot/insurance event (renewal_months, renewal_due_soon_days settings),
  surfaced on the service card and dashboard.
- Service-status card metrics now render as a two-column label/value
  table with row separators instead of wrapping auto-fill grid cells.
- Add a bicycle favicon (favicon.svg) to base + login templates.

Co-Authored-By: opencode <opencode@users.noreply.github.com>

app/templates/dashboard.html

@@ -47,6 +47,8 @@
       {% if s.bike.service_interval_miles %}
         <dt>Every</dt><dd>{{ s.bike.service_interval_miles | money }} mi</dd>
       {% endif %}
+      <dt>MOT</dt><dd><span class="badge {{ renewal_class(s.mot) }}">{{ renewal_text(s.mot) }}</span></dd>
+      <dt>Insurance</dt><dd><span class="badge {{ renewal_class(s.insurance) }}">{{ renewal_text(s.insurance) }}</span></dd>
       <dt>Records</dt><dd>{{ s.event_count }}</dd>
       <dt>Cost to date</dt><dd>{{ s.total_cost | money }}</dd>
     </dl>