feat: portal redesign — shadcn/ui, React Query, Zod, isolated portals

Foundation:
- CLAUDE.md with full coding rules (tech stack, patterns, redirect rules)
- Install @tanstack/react-query, zod, react-hook-form, shadcn/ui deps
- CSS variables design system (Tailwind v4 + tw-animate-css)
- Shared components: Button, Input, Label, Card, Badge, Separator, Form
- PortalLoginShell: two-column login layout (branding left, form right)
- PortalNav: shared sidebar nav used by all portals
- ReactQueryProvider in root layout
- api-client.ts: typed fetch wrapper (no raw fetch in components)

Portal isolation:
- Sidebar now returns null for all non-chapter routes; portals own their layout
- Admin layout: auth guard + PortalNav (slate accent)
- Org layout: auth guard + PortalNav (violet accent)
- Member layout: server-side cookie check → MemberNav client component
- Chapter admin sidebar: PortalNav (blue accent)

Login pages (all use react-hook-form + Zod + PortalLoginShell):
- /login → defaults next to /search (was /) — fixes redirect bug
- /admin/login → replaces /admin
- /org/login → replaces /org
- /member-login → two-step phone+OTP with proper form validation

Portal selector (/) redesigned with accent border-left cards

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

apps/web/app/_components/portal-login-shell.tsx

@@ -0,0 +1,49 @@
+import { cn } from '../_lib/utils';
+
+interface PortalLoginShellProps {
+  title: string;
+  subtitle: string;
+  accentClass?: string;
+  children: React.ReactNode;
+  footer?: React.ReactNode;
+}
+
+export function PortalLoginShell({ title, subtitle, accentClass = 'bg-primary', children, footer }: PortalLoginShellProps) {
+  return (
+    <div className="min-h-screen grid lg:grid-cols-2">
+      {/* Left branding panel */}
+      <div className={cn('hidden lg:flex flex-col justify-between p-10 text-white', accentClass)}>
+        <div className="flex items-center gap-2">
+          <span className="font-bold text-xl tracking-tight">TOWER</span>
+        </div>
+        <div>
+          <blockquote className="space-y-2">
+            <p className="text-lg font-medium leading-relaxed">
+              "Community knowledge, beautifully organised."
+            </p>
+            <footer className="text-sm opacity-70">Insignia TOWER Platform</footer>
+          </blockquote>
+        </div>
+      </div>
+
+      {/* Right form panel */}
+      <div className="flex items-center justify-center p-8 bg-background">
+        <div className="w-full max-w-sm space-y-6">
+          {/* Mobile logo */}
+          <div className="flex items-center gap-2 lg:hidden">
+            <span className="font-bold text-lg">TOWER</span>
+          </div>
+
+          <div className="space-y-1">
+            <h1 className="text-2xl font-bold tracking-tight">{title}</h1>
+            <p className="text-sm text-muted-foreground">{subtitle}</p>
+          </div>
+
+          {children}
+
+          {footer && <div className="text-center text-sm text-muted-foreground">{footer}</div>}
+        </div>
+      </div>
+    </div>
+  );
+}