feat: complete Quantumancy web app — full frontend + docs

Frontend (React 18 + TS + Vite):
- Landing: glitching hero, live /api/stats veil ticker, mode cards, featured spirits
- Séance: three.js shader ghost (hue/form per entity, mood + audio-reactive),
  Ouija planchette board spelling utterances, transcript with TTS replay,
  entity dossier, direct contact streaming, passive/active listening
- Modes: Wire Ghost telemetry panel, EVP mic anomaly detection, WebUSB
  RTL-SDR sweep + waterfall (hardware pass pending), Ouija/Direct Contact
- Codex: public registry + entity dossiers, rarity tiers, i18n EN/ES complete
- State: VeilSocket (reconnect/backoff), seance reducer, auth context
- 72 vitest tests green; served by FastAPI at :7777

Docs: README + as-built plans 3-7

frontend/src/App.tsx

@@ -1,95 +1,32 @@
-import { useEffect, useState } from 'react'
-import { login, logout, me, register, type User } from './api'
+// App shell: router + providers + the global CRT overlay (scanlines/vignette)
+// that sits above every page like old glass.
+
+import { BrowserRouter, Route, Routes } from 'react-router-dom'
+import { AuthProvider } from './state/auth'
+import { CodexEntityPage } from './pages/CodexEntityPage'
+import { CodexPage } from './pages/CodexPage'
+import { EnterPage } from './pages/EnterPage'
+import { LandingPage } from './pages/LandingPage'
+import { SeancePage } from './pages/SeancePage'
 
 function App() {
-  const [user, setUser] = useState<User | null>(null)
-  const [username, setUsername] = useState('')
-  const [password, setPassword] = useState('')
-  const [mode, setMode] = useState<'login' | 'register'>('login')
-  const [error, setError] = useState<string | null>(null)
-  const [checkingSession, setCheckingSession] = useState(true)
-
-  useEffect(() => {
-    me()
-      .then(setUser)
-      .catch(() => setUser(null))
-      .finally(() => setCheckingSession(false))
-  }, [])
-
-  async function handleSubmit(event: React.FormEvent) {
-    event.preventDefault()
-    setError(null)
-    try {
-      if (mode === 'register') {
-        await register(username, password)
-      }
-      const loggedInUser = await login(username, password)
-      setUser(loggedInUser)
-    } catch (err) {
-      setError(err instanceof Error ? err.message : 'Something went wrong')
-    }
-  }
-
-  async function handleLogout() {
-    await logout()
-    setUser(null)
-  }
-
-  if (checkingSession) {
-    return (
-      <main className="app">
-        <p>Listening for a signal...</p>
-      </main>
-    )
-  }
-
   return (
-    <main className="app">
-      <h1>Quantumancy</h1>
-      <p className="tagline">Something is listening on the other side.</p>
-
-      {user ? (
-        <section>
-          <p>Contact established as {user.username}.</p>
-          <button onClick={handleLogout}>End session</button>
-        </section>
-      ) : (
-        <form onSubmit={handleSubmit}>
-          <div className="mode-toggle">
-            <button
-              type="button"
-              className={mode === 'login' ? 'active' : ''}
-              onClick={() => setMode('login')}
-            >
-              Reconnect
-            </button>
-            <button
-              type="button"
-              className={mode === 'register' ? 'active' : ''}
-              onClick={() => setMode('register')}
-            >
-              First contact
-            </button>
-          </div>
-          <label>
-            Username
-            <input value={username} onChange={(e) => setUsername(e.target.value)} required />
-          </label>
-          <label>
-            Password
-            <input
-              type="password"
-              value={password}
-              onChange={(e) => setPassword(e.target.value)}
-              required
-              minLength={8}
-            />
-          </label>
-          {error && <p className="error">{error}</p>}
-          <button type="submit">{mode === 'login' ? 'Enter' : 'Begin'}</button>
-        </form>
-      )}
-    </main>
+    <AuthProvider>
+      <BrowserRouter>
+        <div className="crt-overlay" aria-hidden="true">
+          <div className="crt-scanlines" />
+          <div className="crt-vignette" />
+        </div>
+        <Routes>
+          <Route path="/" element={<LandingPage />} />
+          <Route path="/enter" element={<EnterPage />} />
+          <Route path="/seance" element={<SeancePage />} />
+          <Route path="/codex" element={<CodexPage />} />
+          <Route path="/codex/:id" element={<CodexEntityPage />} />
+          <Route path="*" element={<LandingPage />} />
+        </Routes>
+      </BrowserRouter>
+    </AuthProvider>
   )
 }