feat: add auth pages (login, signup, password reset, onboarding)

- Create stub auth API (lib/auth.ts) with simulated delay
- Add PasswordInput component with visibility toggle
- Add SocialAuthButtons component (Google/Apple placeholders)
- Add AuthLayout with split-panel layout and rotating testimonial
- Implement login page with email/password validation and remember me
- Implement signup page with password strength indicator and ToS checkbox
- Implement forgot-password page with email submission and success state
- Implement reset-password page with token validation from query params
- Implement 4-step onboarding flow (plan selection, watchlist, invites, success)
- Add ToastProvider to root app
- Write 28 tests for all auth components and form validation

web/src/app.tsx

@@ -4,11 +4,13 @@ import { FileRoutes } from "@solidjs/start/router";
 import { Suspense } from "solid-js";
 import { ThemeProvider } from "./lib/theme";
 import { AppShell } from "./components/layout";
+import { ToastProvider } from "./components/ui";
 import "./app.css";
 
 export default function App() {
   return (
     <ThemeProvider>
+    <ToastProvider>
     <Router
       root={(props) => (
         <AppShell>
@@ -18,6 +20,7 @@ export default function App() {
     >
       <FileRoutes />
     </Router>
+    </ToastProvider>
     </ThemeProvider>
   );
 }