Highlight Advance Payment in type dropdown with separator and color

Adds a visual separator line before Advance Payment in the adjustment
type dropdown and styles it with blue color and a triangle marker to
distinguish it from regular adjustment types.

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

core/templates/core/payroll_dashboard.html

@@ -472,7 +472,12 @@
                         <label class="form-label">Type</label>
                         <select name="type" class="form-select" required>
                             {% for code, label in adjustment_types %}
+                                {% if code == 'ADVANCE' %}
+                            <option disabled>────────────────</option>
+                            <option value="{{ code }}" style="color: #0d6efd; font-weight: bold;">&#9654; {{ label }}</option>
+                                {% else %}
                             <option value="{{ code }}">{{ label }}</option>
+                                {% endif %}
                             {% endfor %}
                         </select>
                     </div>