Full site redesign, help system, and dashboard stats fixes

Multi-phase visual facelift (design tokens, dashboards, sidebar/navbar
shell, per-page help guides, and a layout/content pass across every
remaining page) plus backend fixes to the dashboard KPI stats:

- Admin/Supervisor dashboard KPIs (revenue, donations, registrations,
  tickets sold) now use a rolling trailing-month window (today back one
  calendar month, e.g. 9 May - 8 June if today is 8 June) instead of
  calendar month-to-date, which under-counted for most of the month.
  The comparison window shifts the same way, so like is still compared
  with like.
- Reports deep-links from those stat tiles now match the same window
  (range=trailing_month, replacing range=this_month).
- Design tokens (brand-* Tailwind scale + shadcn CSS variables), a
  site-wide contextual help button, fixed dashboard sidebar/navbar,
  Admin/Supervisor/Staff/User dashboard rebuilds backed by a new
  GET /api/stats/overview endpoint, a dedicated Contact page, Site
  Settings restyle with WhatsApp config folded in, and an Account
  activity feed backed by a new SecurityEvent model.
- Every remaining page (home, events, registration flow, auth, legal,
  payment results, and every Admin/Supervisor/Staff/User tool page)
  restyled onto the same design tokens, several with real layout
  upgrades (home hero, events list/detail, donate page, auth pages).
- 20+ new dedicated help guides so the whole site has page-specific
  help content instead of falling back to a generic guide.
- Assorted fixes surfaced along the way: donation-leg double-counting
  in payment stats, donations not counting toward revenue, refund
  netting in per-method report breakdowns, and donation
  over-allocation after a refund.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/src/app/dashboard/staff/event-tickets/page.tsx

@@ -7,6 +7,7 @@ import { useDismissingState } from "@/hooks/useDismissingState";
 import { useRouter, useSearchParams } from "next/navigation";
 import { formatDate } from "@/lib/date";
 import { QrImage } from "@/components/shared/QrImage";
+import { Ticket } from "lucide-react";
 
 function EventTicketsContent() {
   const { token, user } = useAuth();
@@ -229,10 +230,15 @@ function EventTicketsContent() {
 
   return (
       <div className="max-w-6xl mx-auto w-full p-6">
-        <div className="flex items-center justify-between mb-4">
-          <h1 className="text-2xl font-semibold">Event Tickets</h1>
+        <div className="flex items-center justify-between mb-4 flex-wrap gap-3">
+          <div className="flex items-center gap-3">
+            <div className="w-10 h-10 rounded-xl bg-brand-50 flex items-center justify-center shrink-0">
+              <Ticket className="w-5 h-5 text-brand-600" />
+            </div>
+            <h1 className="text-2xl font-semibold text-gray-900">Event Tickets</h1>
+          </div>
           <button
-              className="px-3 py-1.5 text-sm rounded bg-gray-100 hover:bg-gray-200 text-gray-800 shadow-sm"
+              className="px-3 py-1.5 text-sm rounded-lg bg-gray-100 hover:bg-gray-200 text-gray-800 shadow-sm"
               onClick={() => router.push("/dashboard")}
           >
             Back
@@ -325,7 +331,7 @@ function EventTicketsContent() {
                     onClick={() =>
                         printTickets(filteredTickets.filter((t) => !t.isUsed))
                     }
-                    className="px-3 py-2 bg-blue-600 text-white rounded"
+                    className="px-3 py-2 bg-brand-600 hover:bg-brand-700 text-white rounded"
                 >
                   Print unused
                 </button>