feat: Sprint A Wahab review batch — categories, property hierarchy, priority grouping

Items 1-5, 9, 11 from denya-wahab-feedback-s2:
- Category.show_in_form (alert-only flag): Gas Leak hidden from issue picker
  but kept urgent for SLA/alert and reporting; emergency quick path on the
  new-issue form creates urgent tickets via include_hidden categories.
- Seed: Aluminum/Glass, Carpentry, Mould & Damp (Medium default) maintenance
  categories; Lost Property renamed Missing Item (+ sub).
- One alembic migration: add show_in_form (backfill True, Gas Leak False) +
  data rename Lost Property -> Missing Item.
- Property -> Building -> Apartment cascade with searchable apartment combobox
  on the new-issue form and ticket list filters; /api/tickets/units gains
  building filter + /units/grouped variant; /api/tickets gains additive
  building/unit_id filters. apartment_mapping.json committed (deterministic).
- Group-by-priority toggle on /tickets (four sections + unknown bucket,
  age-sortable, composes with filters, URL deep links), FM dashboard active
  tickets, and CS dashboard priority card click-through.
- Tests: 13 new (category visibility, seed idempotency/sync, unit grouping,
  ticket building/unit filters).

app/templates/dashboard/cs.html

@@ -70,23 +70,24 @@
         <!-- Open by Priority -->
         <div class="bg-white rounded-xl shadow-sm border border-gray-200 p-5">
             <h3 class="text-sm font-semibold text-gray-700 uppercase tracking-wide mb-4">Open by Priority</h3>
-            <div class="space-y-3">
-                <div class="flex items-center justify-between">
+            <div class="space-y-2">
+                <a href="/tickets?group=priority&priority=urgent" class="flex items-center justify-between rounded-lg px-2 py-1.5 hover:bg-red-50 transition">
                     <span class="text-red-600 font-medium">🔴 Urgent</span>
                     <span class="text-2xl font-bold" x-text="kpi.byPriority?.urgent || 0"></span>
-                </div>
-                <div class="flex items-center justify-between">
+                </a>
+                <a href="/tickets?group=priority&priority=high" class="flex items-center justify-between rounded-lg px-2 py-1.5 hover:bg-orange-50 transition">
                     <span class="text-orange-600 font-medium">🟠 High</span>
                     <span class="text-2xl font-bold" x-text="kpi.byPriority?.high || 0"></span>
-                </div>
-                <div class="flex items-center justify-between">
+                </a>
+                <a href="/tickets?group=priority&priority=medium" class="flex items-center justify-between rounded-lg px-2 py-1.5 hover:bg-yellow-50 transition">
                     <span class="text-yellow-600 font-medium">🟡 Medium</span>
                     <span class="text-2xl font-bold" x-text="kpi.byPriority?.medium || 0"></span>
-                </div>
-                <div class="flex items-center justify-between">
+                </a>
+                <a href="/tickets?group=priority&priority=low" class="flex items-center justify-between rounded-lg px-2 py-1.5 hover:bg-green-50 transition">
                     <span class="text-green-600 font-medium">🟢 Low</span>
                     <span class="text-2xl font-bold" x-text="kpi.byPriority?.low || 0"></span>
-                </div>
+                </a>
+                <p class="text-[11px] text-gray-400 pt-1">Click a row to open the priority-grouped queue.</p>
             </div>
         </div>