feat: fase 2+3 — expansion masiva multi-perfil + bug fixes + hardening

Fase 2 (expansion):
- Francesca: +6 etapas matematicas (5-10), +7 etapas lectura (3-9), +2 ortografia
- Sebastian: +8 etapas matematicas (4-11), +6 lectura, +3 historia, +3 geografia, +1 banderas
- Nuevas paginas: ortografia, lectura, geografia, matematicas
- ~900 ejercicios nuevos, paridad ~500 por perfil

Fase 3 (bug fixes + hardening):
- Fix: SessionLog auto-create en grade route
- Fix: engine cache (no borrar antes de revisar)
- Fix: FSRS cards actualizadas en flujo curriculum
- Fix: responseMs real (no hardcodeado 3000)
- Fix: options dentro de content en sebastian etapa-1
- Fix: trazo-letra consonantes crash
- Security: execFileSync anti-command-injection en TTS
- DB: 18 cascade deletes + indices + unique constraints
- APIs debug: reset, state, seed
- Docker: espeak-ng + prisma + user/group
- E2E: 23 tests nuevos (curriculum-flow.spec.ts)
- Code review: tailwind colors, middleware dev mode, eslint config

Verificado: tsc exit 0, build exit 0, 61 E2E tests pass

app/page.tsx

@@ -4,9 +4,30 @@ import { useEffect } from "react"
 import { useRouter } from "next/navigation"
 
 const PROFILES = [
-  { id: "isabella", label: "Isabella", emoji: "👧", color: "bg-pink-500" },
-  { id: "francesca", label: "Francesca", emoji: "👦", color: "bg-blue-500" },
-  { id: "sebastian", label: "Sebastián", emoji: "🧒", color: "bg-green-500" },
+  {
+    id: "isabella",
+    label: "Isabella",
+    edad: "4 años",
+    emoji: "👧",
+    color: "from-pink-400 to-pink-500",
+    desc: "Letras, números y primeras palabras",
+  },
+  {
+    id: "francesca",
+    label: "Francesca",
+    edad: "6 años",
+    emoji: "👦",
+    color: "from-blue-400 to-blue-500",
+    desc: "Matemáticas, lectura y ortografía",
+  },
+  {
+    id: "sebastian",
+    label: "Sebastián",
+    edad: "8 años",
+    emoji: "🧒",
+    color: "from-green-400 to-green-500",
+    desc: "Matemáticas avanzadas, historia y geografía",
+  },
 ]
 
 export default function RootPage() {
@@ -16,32 +37,57 @@ export default function RootPage() {
     const host = window.location.hostname
     if (host.includes("simulacro")) {
       router.replace("/parent")
-      return
-    }
-
-    const params = new URLSearchParams(window.location.search)
-    const preselected = params.get("profile")
-    if (preselected && PROFILES.find(p => p.id === preselected)) {
-      router.replace(`/child/${preselected}`)
     }
   }, [router])
 
+  const handleSelect = (id: string) => {
+    if (id === "isabella") {
+      router.push("/child")
+    } else {
+      router.push(`/${id}`)
+    }
+  }
+
   return (
-    <div className="min-h-dvh bg-background flex flex-col items-center justify-center p-6 gap-8">
-      <h1 className="text-4xl font-display font-bold text-center">¿Quién sos?</h1>
+    <div className="min-h-dvh bg-background flex flex-col items-center justify-center p-6 gap-6 relative overflow-hidden">
+      {/* Background decoration */}
+      <div className="absolute top-0 left-0 w-full h-1 bg-gradient-to-r from-primary via-accent to-secondary opacity-30" />
+
+      {/* Logo area */}
+      <div className="text-center space-y-1 mb-4">
+        <div className="text-5xl">📚</div>
+        <h1 className="text-3xl font-display font-bold text-foreground">
+          EduEasy
+        </h1>
+        <p className="text-muted-foreground text-sm">¿Quién va a aprender hoy?</p>
+      </div>
 
       <div className="flex flex-col gap-4 w-full max-w-sm">
         {PROFILES.map((p) => (
           <button
             key={p.id}
-            onClick={() => router.push(`/child/${p.id}`)}
-            className={`${p.color} text-white touch-target-lg rounded-2xl flex items-center gap-4 px-6 py-8 text-2xl font-display font-bold shadow-lg active:scale-95 transition-transform`}
+            onClick={() => handleSelect(p.id)}
+            className={`bg-gradient-to-r ${p.color} text-white touch-target-lg rounded-2xl flex items-center gap-4 px-6 py-6 text-left shadow-lg active:scale-95 transition-all hover:shadow-xl font-display`}
           >
-            <span className="text-4xl">{p.emoji}</span>
-            <span>{p.label}</span>
+            <span className="text-5xl shrink-0">{p.emoji}</span>
+            <div className="flex-1 min-w-0">
+              <div className="text-xl font-bold">{p.label}</div>
+              <div className="text-sm opacity-80">{p.edad}</div>
+              <div className="text-xs opacity-70 mt-1">{p.desc}</div>
+            </div>
+            <span className="text-2xl opacity-60">→</span>
           </button>
         ))}
       </div>
+
+      <div className="fixed bottom-4 text-center">
+        <button
+          onClick={() => router.push("/parent")}
+          className="text-sm text-muted-foreground underline underline-offset-2"
+        >
+          Mamá / Papá
+        </button>
+      </div>
     </div>
   )
 }