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/tailwind.config.js

@@ -1,9 +1,68 @@
+/** @type {import('tailwindcss').Config} */
 module.exports = {
 	content: [
 		"./src/**/*.{js,ts,jsx,tsx}",
 	],
 	theme: {
-		extend: {},
+		extend: {
+			colors: {
+				border: "hsl(var(--border))",
+				input: "hsl(var(--input))",
+				ring: "hsl(var(--ring))",
+				background: "hsl(var(--background))",
+				foreground: "hsl(var(--foreground))",
+				primary: {
+					DEFAULT: "hsl(var(--primary))",
+					foreground: "hsl(var(--primary-foreground))",
+				},
+				secondary: {
+					DEFAULT: "hsl(var(--secondary))",
+					foreground: "hsl(var(--secondary-foreground))",
+				},
+				destructive: {
+					DEFAULT: "hsl(var(--destructive))",
+					foreground: "hsl(var(--destructive-foreground))",
+				},
+				muted: {
+					DEFAULT: "hsl(var(--muted))",
+					foreground: "hsl(var(--muted-foreground))",
+				},
+				accent: {
+					DEFAULT: "hsl(var(--accent))",
+					foreground: "hsl(var(--accent-foreground))",
+				},
+				popover: {
+					DEFAULT: "hsl(var(--popover))",
+					foreground: "hsl(var(--popover-foreground))",
+				},
+				card: {
+					DEFAULT: "hsl(var(--card))",
+					foreground: "hsl(var(--card-foreground))",
+				},
+				// Fixed indigo/purple brand scale — the site's hard-coded design-system
+				// color. Use this (not `indigo-*`/`blue-*` literals) for anything that
+				// isn't a shadcn primitive: nav active-states, icon chips, the help FAB,
+				// etc. Never bind this scale to the admin-configurable accent_color
+				// setting (see globals.css) — that stays an inline style on the org name only.
+				brand: {
+					50: "#EEF2FF",
+					100: "#E0E7FF",
+					200: "#C7D2FE",
+					300: "#A5B4FC",
+					400: "#818CF8",
+					500: "#6366F1",
+					600: "#4F46E5",
+					700: "#4338CA",
+					800: "#3730A3",
+					900: "#312E81",
+				},
+			},
+			borderRadius: {
+				lg: "var(--radius)",
+				md: "calc(var(--radius) - 2px)",
+				sm: "calc(var(--radius) - 4px)",
+			},
+		},
 	},
-	plugins: [],
+	plugins: [require("tailwindcss-animate")],
 };