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/(auth)/forgot-password/page.tsx

@@ -3,6 +3,7 @@ import { useState } from "react";
 import { Navbar } from "@/components/layout/Navbar";
 import { Footer } from "@/components/layout/Footer";
 import { apiFetch } from "@/lib/api";
+import { KeyRound } from "lucide-react";
 
 export default function ForgotPasswordPage() {
     const [email, setEmail] = useState("");
@@ -32,16 +33,21 @@ export default function ForgotPasswordPage() {
     return (
         <div className="min-h-screen flex flex-col">
             <Navbar />
-            <main className="flex-1 px-4 py-10 max-w-md mx-auto w-full">
-                <div className="border rounded-xl p-6 bg-white shadow-sm">
-                    <h1 className="text-2xl font-semibold mb-4">Forgot your password?</h1>
-                    <p className="text-gray-700 mb-6">Enter your account email and we'll send you a link to reset your password.</p>
+            <main className="flex-1 flex items-center justify-center p-6 bg-gradient-to-br from-brand-50 via-white to-brand-50">
+                <div className="w-full max-w-md border rounded-2xl p-8 bg-white shadow-sm">
+                    <div className="flex items-center gap-3 mb-6">
+                        <div className="w-11 h-11 rounded-xl bg-brand-50 flex items-center justify-center shrink-0">
+                            <KeyRound className="w-5 h-5 text-brand-600" />
+                        </div>
+                        <h1 className="text-xl font-semibold text-gray-900">Forgot your password?</h1>
+                    </div>
+                    <p className="text-gray-600 text-sm mb-6">Enter your account email and we'll send you a link to reset your password.</p>
                     <form onSubmit={submit} className="space-y-4">
                         <div>
                             <label className="block text-sm font-medium mb-1">Email</label>
                             <input type="email" value={email} onChange={e => setEmail(e.target.value)} required className="w-full border rounded px-3 py-2" />
                         </div>
-                        <button disabled={loading || !email} className="px-4 py-2 rounded bg-blue-600 text-white disabled:opacity-60">
+                        <button disabled={loading || !email} className="px-4 py-2 rounded bg-brand-600 hover:bg-brand-700 text-white disabled:opacity-60">
                             {loading ? "Sending..." : "Send reset link"}
                         </button>
                     </form>

frontend/src/app/(auth)/login/page.tsx

@@ -3,14 +3,23 @@ import React, { Suspense } from "react";
 import { Navbar } from "@/components/layout/Navbar";
 import { Footer } from "@/components/layout/Footer";
 import { LoginForm } from "@/components/auth/LoginForm";
+import { LogIn } from "lucide-react";
 
 export default function LoginPage() {
   return (
     <div className="min-h-screen flex flex-col">
       <Navbar />
-      <main className="flex-1 flex items-center justify-center p-6">
-        <div className="w-full max-w-md">
-          <h1 className="text-2xl font-semibold mb-4">Login</h1>
+      <main className="flex-1 flex items-center justify-center p-6 bg-gradient-to-br from-brand-50 via-white to-brand-50">
+        <div className="w-full max-w-md border rounded-2xl p-8 bg-white shadow-sm">
+          <div className="flex items-center gap-3 mb-6">
+            <div className="w-11 h-11 rounded-xl bg-brand-50 flex items-center justify-center shrink-0">
+              <LogIn className="w-5 h-5 text-brand-600" />
+            </div>
+            <div>
+              <h1 className="text-xl font-semibold text-gray-900">Welcome back</h1>
+              <p className="text-sm text-gray-500">Log in to manage your events and tickets.</p>
+            </div>
+          </div>
           <Suspense fallback={<div />}>
             <LoginForm />
           </Suspense>

frontend/src/app/(auth)/register/page.tsx

@@ -3,14 +3,23 @@ import React, { Suspense } from "react";
 import { Navbar } from "@/components/layout/Navbar";
 import { Footer } from "@/components/layout/Footer";
 import { RegisterForm } from "@/components/auth/RegisterForm";
+import { UserPlus } from "lucide-react";
 
 export default function RegisterPage() {
   return (
     <div className="min-h-screen flex flex-col">
       <Navbar />
-      <main className="flex-1 flex items-center justify-center p-6">
-        <div className="w-full max-w-md">
-          <h1 className="text-2xl font-semibold mb-4">Create Account</h1>
+      <main className="flex-1 flex items-center justify-center p-6 bg-gradient-to-br from-brand-50 via-white to-brand-50">
+        <div className="w-full max-w-md border rounded-2xl p-8 bg-white shadow-sm">
+          <div className="flex items-center gap-3 mb-6">
+            <div className="w-11 h-11 rounded-xl bg-brand-50 flex items-center justify-center shrink-0">
+              <UserPlus className="w-5 h-5 text-brand-600" />
+            </div>
+            <div>
+              <h1 className="text-xl font-semibold text-gray-900">Create account</h1>
+              <p className="text-sm text-gray-500">One account for all your registrations and tickets.</p>
+            </div>
+          </div>
           <Suspense fallback={<div />}>
             <RegisterForm />
           </Suspense>