Refactor code structure for improved readability and maintainability

docs/BROCHURE_STUDIO.md

@@ -0,0 +1,66 @@
+# Brochure Comercial - Plataforma Studio
+
+## 1) Qué es Studio
+Studio es la plataforma de autoría académica de OpenCCB para diseñar, publicar y administrar cursos de alta fidelidad. Está orientada a instituciones educativas, equipos académicos y docentes que necesitan construir experiencias de aprendizaje interactivas sin fricción técnica.
+
+## 2) Propuesta de valor
+- Diseño instruccional en un entorno moderno y visual.
+- Creación de lecciones modulares con bloques interactivos.
+- Banco de preguntas reutilizable para evaluaciones.
+- Gestión de usuarios, cursos y configuraciones institucionales.
+- Integración con LMS Experience para consumo de contenidos por estudiantes.
+
+## 3) Capacidades principales
+- Gestión de cursos: creación, edición, estructura por módulos y lecciones.
+- Constructor de lecciones: bloques de texto, multimedia, quiz, respuestas cortas, ordenamiento, matching, hotspot, audio-response, peer review, role-playing y mermaid.
+- Plantillas: plantillas de curso y de pruebas para estandarizar procesos.
+- Biblioteca de assets: administración y reutilización de recursos multimedia.
+- Banco de preguntas: catálogo de preguntas filtrable por tipo y dificultad.
+- Analítica y seguimiento: soporte para revisión de progreso y evaluaciones.
+- Branding institucional: logo, favicon y colores de marca.
+
+## 4) Beneficios para la institución
+- Reduce tiempos de producción académica.
+- Estandariza calidad de contenidos.
+- Facilita colaboración entre docentes y equipos de diseño instruccional.
+- Mejora la trazabilidad de evaluaciones y resultados.
+- Acelera despliegues de nuevos programas y cursos.
+
+## 5) Flujo recomendado de uso
+1. Configurar branding institucional.
+2. Crear curso y definir módulos.
+3. Diseñar lecciones con bloques interactivos.
+4. Configurar evaluaciones y rúbricas.
+5. Publicar y monitorear desempeño.
+
+## 6) Capturas sugeridas (fotos)
+Pantalla de acceso
+
+![Pantalla de acceso](assets/studio/01-login-studio.png)
+
+Vista principal de cursos
+
+![Dashboard de cursos](assets/studio/02-dashboard-cursos.png)
+
+Editor de lección con bloques
+
+![Editor de leccion](assets/studio/03-editor-leccion.png)
+
+Banco de preguntas y filtros
+
+![Banco de preguntas](assets/studio/04-banco-preguntas.png)
+
+Librería de recursos
+
+![Libreria de assets](assets/studio/05-library-assets.png)
+
+Editor de rúbricas
+
+![Rubricas](assets/studio/06-rubricas.png)
+
+Administración de usuarios
+
+![Administracion de usuarios](assets/studio/07-admin-usuarios.png)
+
+## 7) Mensaje comercial breve
+Studio convierte el diseño académico en un proceso más rápido, controlado y escalable. Permite a la institución pasar de la idea al curso publicado con calidad pedagógica y consistencia operacional.

docs/MANUAL_USUARIO_STUDIO.md

@@ -0,0 +1,140 @@
+# Manual de Usuario - Plataforma Studio
+
+## 1) Objetivo
+Este manual explica cómo usar Studio para crear y administrar cursos, lecciones y evaluaciones.
+
+## 2) Perfil de usuario
+- Docentes
+- Diseñadores instruccionales
+- Administradores académicos
+
+## 3) Acceso a la plataforma
+1. Ir a Studio en el navegador.
+2. Iniciar sesión con credenciales institucionales.
+3. Verificar que el menú principal muestre los módulos habilitados para el rol.
+
+Captura recomendada:
+
+![Login Studio](assets/studio/01-login-studio.png)
+
+## 4) Navegación principal
+- Cursos: listado y gestión de cursos.
+- Librería: administración de archivos y recursos.
+- Banco de preguntas: creación y reutilización de preguntas.
+- Plantillas: estandarización de contenidos.
+- Configuración: opciones de perfil y parámetros generales.
+
+Captura recomendada:
+
+![Dashboard de cursos](assets/studio/02-dashboard-cursos.png)
+
+## 5) Crear un curso
+1. Entrar a Cursos.
+2. Seleccionar Crear curso.
+3. Definir título y descripción.
+4. Guardar para habilitar el editor completo.
+
+Buenas prácticas:
+- Usar nombres claros por nivel/tema.
+- Definir objetivos de aprendizaje desde el inicio.
+
+## 6) Editar estructura (módulos y lecciones)
+1. Abrir un curso.
+2. Crear módulos.
+3. Agregar lecciones por módulo.
+4. Ordenar secuencia de aprendizaje.
+
+Captura recomendada:
+
+![Editor de lección](assets/studio/03-editor-leccion.png)
+
+## 7) Constructor de lecciones por bloques
+Tipos recomendados de bloque:
+- Description
+- Media
+- Quiz
+- Fill in the blanks
+- Matching
+- Ordering
+- Short answer
+- Hotspot
+- Audio response
+- Peer review
+- Role playing
+- Mermaid
+
+Flujo:
+1. Agregar bloque.
+2. Configurar contenido e instrucciones.
+3. Guardar cambios.
+4. Previsualizar.
+
+## 8) Banco de preguntas
+1. Entrar a Banco de preguntas.
+2. Crear nueva pregunta.
+3. Definir tipo, dificultad y enunciado.
+4. Guardar y reutilizar en evaluaciones.
+
+Captura recomendada:
+
+![Banco de preguntas](assets/studio/04-banco-preguntas.png)
+
+## 9) Libreria de assets
+1. Subir recursos (imágenes, audio, documentos).
+2. Etiquetar y organizar.
+3. Insertar recursos desde lecciones.
+
+Captura recomendada:
+
+![Librería de assets](assets/studio/05-library-assets.png)
+
+## 10) Rúbricas de evaluación
+1. Crear rúbrica por curso o actividad.
+2. Definir criterios y niveles.
+3. Asignar puntajes por nivel.
+4. Guardar al finalizar la edición.
+
+Captura recomendada:
+
+![Rúbricas](assets/studio/06-rubricas.png)
+
+## 11) Administración de usuarios (rol admin)
+1. Entrar al panel de administración.
+2. Buscar usuario.
+3. Editar rol o estado.
+4. Guardar cambios.
+
+Captura recomendada:
+
+![Administración de usuarios](assets/studio/07-admin-usuarios.png)
+
+## 12) Solución de problemas comunes
+- No veo menús esperados:
+  Verificar sesión activa y rol del usuario.
+- No se guardan cambios:
+  Confirmar conexión y permisos del curso.
+- Recursos no cargan:
+  Revisar formatos permitidos y tamaño del archivo.
+
+## 13) Recomendaciones operativas
+- Definir convención de nombres para cursos y módulos.
+- Usar plantillas para mantener estándar pedagógico.
+- Revisar cada lección en previsualización antes de publicar.
+- Mantener el banco de preguntas limpio y etiquetado.
+
+## 14) Checklist de publicacion
+- Objetivos definidos.
+- Lecciones ordenadas.
+- Bloques revisados.
+- Evaluaciones probadas.
+- Rúbricas listas.
+- Recursos multimedia verificados.
+
+## 15) Anexo: inventario de fotos para documentación
+- docs/assets/studio/01-login-studio.png
+- docs/assets/studio/02-dashboard-cursos.png
+- docs/assets/studio/03-editor-leccion.png
+- docs/assets/studio/04-banco-preguntas.png
+- docs/assets/studio/05-library-assets.png
+- docs/assets/studio/06-rubricas.png
+- docs/assets/studio/07-admin-usuarios.png

nginx/learning.conf

@@ -13,6 +13,29 @@ location /lms-api/ {
 }
 
 location /cms-api/ {
+    # CORS safety net at proxy level for CMS API.
+    set $cors_origin "";
+    if ($http_origin ~* "^https?://([a-z0-9-]+\\.)?norteamericano\\.(com|cl)$") {
+        set $cors_origin $http_origin;
+    }
+    if ($http_origin ~* "^http://localhost(:[0-9]+)?$") {
+        set $cors_origin $http_origin;
+    }
+
+    if ($request_method = OPTIONS) {
+        add_header Access-Control-Allow-Origin $cors_origin always;
+        add_header Vary "Origin, Access-Control-Request-Method, Access-Control-Request-Headers" always;
+        add_header Access-Control-Allow-Methods "GET,POST,PUT,DELETE,OPTIONS,PATCH,HEAD" always;
+        add_header Access-Control-Allow-Headers "content-type,authorization,x-requested-with,x-organization-id,range" always;
+        add_header Access-Control-Max-Age 86400 always;
+        add_header Content-Length 0 always;
+        add_header Content-Type "text/plain; charset=utf-8" always;
+        return 204;
+    }
+
+    add_header Access-Control-Allow-Origin $cors_origin always;
+    add_header Vary "Origin" always;
+
     rewrite ^/cms-api/(.*)$ /$1 break;
     proxy_pass http://openccb-studio:3001;
     proxy_set_header Host $host;

nginx/studio.conf

@@ -9,6 +9,29 @@ client_body_timeout 1800s;
 # Prefer the explicit `/cms-api/*` prefix for frontend fetches. This avoids collisions
 # with Next.js pages like `/courses` and `/admin` that share the same host.
 location /cms-api/ {
+    # CORS safety net at proxy level for CMS API.
+    set $cors_origin "";
+    if ($http_origin ~* "^https?://([a-z0-9-]+\\.)?norteamericano\\.(com|cl)$") {
+        set $cors_origin $http_origin;
+    }
+    if ($http_origin ~* "^http://localhost(:[0-9]+)?$") {
+        set $cors_origin $http_origin;
+    }
+
+    if ($request_method = OPTIONS) {
+        add_header Access-Control-Allow-Origin $cors_origin always;
+        add_header Vary "Origin, Access-Control-Request-Method, Access-Control-Request-Headers" always;
+        add_header Access-Control-Allow-Methods "GET,POST,PUT,DELETE,OPTIONS,PATCH,HEAD" always;
+        add_header Access-Control-Allow-Headers "content-type,authorization,x-requested-with,x-organization-id,range" always;
+        add_header Access-Control-Max-Age 86400 always;
+        add_header Content-Length 0 always;
+        add_header Content-Type "text/plain; charset=utf-8" always;
+        return 204;
+    }
+
+    add_header Access-Control-Allow-Origin $cors_origin always;
+    add_header Vary "Origin" always;
+
     rewrite ^/cms-api/(.*)$ /$1 break;
     proxy_pass http://openccb-studio:3001;
     proxy_request_buffering off;

services/cms-service/src/handlers_question_bank.rs

@@ -47,6 +47,47 @@ source_asset_id,
 unit_number
 "#;
 
+fn normalize_answer_keywords_value(value: serde_json::Value) -> serde_json::Value {
+    match value {
+        serde_json::Value::Array(items) => serde_json::Value::Array(
+            items
+                .into_iter()
+                .map(normalize_answer_keywords_value)
+                .collect(),
+        ),
+        serde_json::Value::Object(map) => {
+            let answer_text = map
+                .get("answer")
+                .and_then(|v| v.as_str())
+                .map(|s| s.to_string());
+
+            if map.contains_key("keywords") {
+                if let Some(answer) = answer_text {
+                    return serde_json::Value::String(answer);
+                }
+            }
+
+            let normalized_map = map
+                .into_iter()
+                .map(|(k, v)| (k, normalize_answer_keywords_value(v)))
+                .collect();
+
+            serde_json::Value::Object(normalized_map)
+        }
+        other => other,
+    }
+}
+
+fn normalize_question_bank_payload_values(
+    options: Option<serde_json::Value>,
+    correct_answer: Option<serde_json::Value>,
+) -> (Option<serde_json::Value>, Option<serde_json::Value>) {
+    (
+        options.map(normalize_answer_keywords_value),
+        correct_answer.map(normalize_answer_keywords_value),
+    )
+}
+
 async fn connect_mysql_pool(env_var: &str) -> Result<sqlx::MySqlPool, (StatusCode, String)> {
     use sqlx::mysql::MySqlPoolOptions;
 
@@ -288,6 +329,23 @@ pub async fn create_question(
     State(pool): State<PgPool>,
     Json(payload): Json<CreateQuestionBankPayload>,
 ) -> Result<Json<QuestionBank>, (StatusCode, String)> {
+    let CreateQuestionBankPayload {
+        question_text,
+        question_type,
+        options,
+        correct_answer,
+        explanation,
+        points,
+        difficulty,
+        tags,
+        media_url,
+        media_type,
+        skill_assessed,
+    } = payload;
+
+    let (normalized_options, normalized_correct_answer) =
+        normalize_question_bank_payload_values(options, correct_answer);
+
     let create_question_sql = format!(
         r#"
         INSERT INTO question_bank (
@@ -306,17 +364,17 @@ pub async fn create_question(
     )
     .bind(org_ctx.id)
     .bind(claims.sub)
-    .bind(&payload.question_text)
+    .bind(&question_text)
-    .bind(&payload.question_type)
+    .bind(&question_type)
-    .bind(&payload.options)
+    .bind(&normalized_options)
-    .bind(&payload.correct_answer)
+    .bind(&normalized_correct_answer)
-    .bind(&payload.explanation)
+    .bind(&explanation)
-    .bind(payload.points.unwrap_or(1))
+    .bind(points.unwrap_or(1))
-    .bind(payload.difficulty.as_deref().unwrap_or("medium"))
+    .bind(difficulty.as_deref().unwrap_or("medium"))
-    .bind(payload.tags.as_deref())
+    .bind(tags.as_deref())
-    .bind(payload.skill_assessed.as_deref())
+    .bind(skill_assessed.as_deref())
-    .bind(payload.media_url.as_deref())
+    .bind(media_url.as_deref())
-    .bind(payload.media_type.as_deref())
+    .bind(media_type.as_deref())
     .fetch_one(&pool)
     .await
     .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
@@ -486,6 +544,22 @@ pub async fn update_question(
     State(pool): State<PgPool>,
     Json(payload): Json<UpdateQuestionBankPayload>,
 ) -> Result<Json<QuestionBank>, (StatusCode, String)> {
+    let UpdateQuestionBankPayload {
+        question_text,
+        question_type,
+        options,
+        correct_answer,
+        explanation,
+        points,
+        difficulty,
+        tags,
+        is_active,
+        is_archived,
+    } = payload;
+
+    let (normalized_options, normalized_correct_answer) =
+        normalize_question_bank_payload_values(options, correct_answer);
+
     let update_question_sql = format!(
         r#"
         UPDATE question_bank
@@ -512,16 +586,16 @@ pub async fn update_question(
     )
     .bind(id)
     .bind(org_ctx.id)
-    .bind(payload.question_text)
+    .bind(question_text)
-    .bind(payload.question_type.map(|t| t.to_string()))
+    .bind(question_type.map(|t| t.to_string()))
-    .bind(&payload.options)
+    .bind(&normalized_options)
-    .bind(&payload.correct_answer)
+    .bind(&normalized_correct_answer)
-    .bind(&payload.explanation)
+    .bind(&explanation)
-    .bind(payload.points)
+    .bind(points)
-    .bind(payload.difficulty)
+    .bind(difficulty)
-    .bind(payload.tags.as_deref())
+    .bind(tags.as_deref())
-    .bind(payload.is_active)
+    .bind(is_active)
-    .bind(payload.is_archived)
+    .bind(is_archived)
     .fetch_one(&pool)
     .await
     .map_err(|e| match e {

services/cms-service/src/handlers_test_templates.rs

@@ -13,6 +13,47 @@ use sqlx::PgPool;
 use std::time::Duration;
 use uuid::Uuid;
 
+fn normalize_answer_keywords_value(value: serde_json::Value) -> serde_json::Value {
+    match value {
+        serde_json::Value::Array(items) => serde_json::Value::Array(
+            items
+                .into_iter()
+                .map(normalize_answer_keywords_value)
+                .collect(),
+        ),
+        serde_json::Value::Object(map) => {
+            let answer_text = map
+                .get("answer")
+                .and_then(|v| v.as_str())
+                .map(|s| s.to_string());
+
+            if map.contains_key("keywords") {
+                if let Some(answer) = answer_text {
+                    return serde_json::Value::String(answer);
+                }
+            }
+
+            let normalized_map = map
+                .into_iter()
+                .map(|(k, v)| (k, normalize_answer_keywords_value(v)))
+                .collect();
+
+            serde_json::Value::Object(normalized_map)
+        }
+        other => other,
+    }
+}
+
+fn normalize_question_bank_payload_values(
+    options: Option<serde_json::Value>,
+    correct_answer: Option<serde_json::Value>,
+) -> (Option<serde_json::Value>, Option<serde_json::Value>) {
+    (
+        options.map(normalize_answer_keywords_value),
+        correct_answer.map(normalize_answer_keywords_value),
+    )
+}
+
 // ==================== Query Parameters ====================
 
 #[derive(Debug, Deserialize)]
@@ -1736,6 +1777,12 @@ pub async fn generate_questions_with_rag(
             _ => common::models::QuestionBankType::MultipleChoice,
         };
 
+        let (normalized_options, normalized_correct_answer) =
+            normalize_question_bank_payload_values(
+                question.options.clone(),
+                question.correct_answer.clone(),
+            );
+
         let result = sqlx::query(
             r#"
             INSERT INTO question_bank (
@@ -1750,8 +1797,8 @@ pub async fn generate_questions_with_rag(
         .bind(claims.sub)
         .bind(&question.question_text)
         .bind(&question_type)
-        .bind(&question.options)
+        .bind(&normalized_options)
-        .bind(&question.correct_answer)
+        .bind(&normalized_correct_answer)
         .bind(&question.explanation)
         .bind(question.points)
         .bind("medium")

services/cms-service/src/main.rs

@@ -27,7 +27,7 @@ use sqlx::postgres::PgPoolOptions;
 use std::env;
 use std::net::SocketAddr;
 use std::time::Duration;
-use tower_http::cors::{Any, CorsLayer};
+use tower_http::cors::CorsLayer;
 use tower_http::set_header::SetResponseHeaderLayer;
 use tower_http::trace::TraceLayer;
 
@@ -114,8 +114,14 @@ async fn main() {
                 "http://192.168.0.254:3000",
                 "http://192.168.0.254:3003",
                 "http://192.168.0.254",
-                // Production - Norteamericano domains (HTTPS)
+                // Production - Norteamericano domains (.cl and .com)
+                "http://studio.norteamericano.com",
+                "https://studio.norteamericano.com",
+                "http://learning.norteamericano.com",
+                "https://learning.norteamericano.com",
+                "http://studio.norteamericano.cl",
                 "https://studio.norteamericano.cl",
+                "http://learning.norteamericano.cl",
                 "https://learning.norteamericano.cl",
             ];
             
@@ -124,17 +130,21 @@ async fn main() {
                 return true;
             }
             
-            // Check wildcard for subdomains: https://*.norteamericano.cl
+            // Check wildcard for subdomains in norteamericano.cl/.com over HTTP(S)
-            if origin_str.starts_with("https://") && origin_str.ends_with(".norteamericano.cl") {
+            for scheme in ["http://", "https://"] {
-                let subdomain = origin_str
+                for domain in [".norteamericano.cl", ".norteamericano.com"] {
-                    .strip_prefix("https://")
+                    if origin_str.starts_with(scheme) && origin_str.ends_with(domain) {
-                    .unwrap_or("")
+                        let subdomain = origin_str
-                    .strip_suffix(".norteamericano.cl")
+                            .strip_prefix(scheme)
-                    .unwrap_or("");
+                            .unwrap_or("")
+                            .strip_suffix(domain)
+                            .unwrap_or("");
 
-                // Allow any subdomain (e.g., api., cdn., admin., etc.)
+                        // Allow any subdomain (e.g., api., cdn., admin., etc.)
-                if !subdomain.is_empty() && !subdomain.contains('/') {
+                        if !subdomain.is_empty() && !subdomain.contains('/') {
-                    return true;
+                            return true;
+                        }
+                    }
                 }
             }
             

web/studio/src/app/question-bank/page.tsx

@@ -1,11 +1,10 @@
 'use client';
 
-import React, { useState, useEffect } from 'react';
+import React, { useState, useEffect, useCallback } from 'react';
-import { questionBankApi, QuestionBank, QuestionBankFilters, QuestionBankType } from '@/lib/api';
+import { questionBankApi, QuestionBank, QuestionBankFilters } from '@/lib/api';
 import {
-    Plus, Search, Filter, Edit2, Trash2, Download,
+    Plus, Search, Filter,
-    Upload, Sparkles, ChevronDown, ChevronUp, X, Check, AlertCircle,
+    Upload, BookOpen
-    Headphones, BookOpen, Tag, Hash, Globe
 } from 'lucide-react';
 import QuestionBankEditor from '@/components/QuestionBank/QuestionBankEditor';
 import QuestionBankCard from '@/components/QuestionBank/QuestionBankCard';
@@ -15,6 +14,68 @@ const isMySqlOrigin = (source?: string) => source === 'imported-mysql' || source
 const isMaterialsOrigin = (source?: string) => source === 'imported-material';
 const isAiOrigin = (source?: string) => source === 'ai-generated';
 
+const toSafeText = (value: unknown): string => {
+    if (value === null || value === undefined) return '';
+    if (typeof value === 'string' || typeof value === 'number' || typeof value === 'boolean') {
+        return String(value);
+    }
+    if (Array.isArray(value)) {
+        return value.map((v) => toSafeText(v)).filter(Boolean).join(', ');
+    }
+    if (typeof value === 'object') {
+        const obj = value as Record<string, unknown>;
+        if (typeof obj.answer === 'string') return obj.answer;
+        if (typeof obj.text === 'string') return obj.text;
+        if (typeof obj.label === 'string') return obj.label;
+        try {
+            return JSON.stringify(obj);
+        } catch {
+            return '';
+        }
+    }
+    return '';
+};
+
+const sanitizeQuestion = (q: QuestionBank): QuestionBank => {
+    const safeTags = Array.isArray(q.tags)
+        ? q.tags.map((t) => toSafeText(t)).filter(Boolean)
+        : [];
+
+    const safeOptions = Array.isArray(q.options)
+        ? q.options.map((opt) => {
+            if (typeof opt === 'object' && opt !== null) {
+                const item = opt as Record<string, unknown>;
+                if ('answer' in item || 'keywords' in item) {
+                    return toSafeText(item.answer ?? item.text ?? item.label ?? item);
+                }
+            }
+            return opt;
+        })
+        : q.options;
+
+    const safeCorrectAnswer = (() => {
+        const raw = q.correct_answer;
+        if (Array.isArray(raw)) {
+            return raw.map((item) => toSafeText(item));
+        }
+        if (raw && typeof raw === 'object') {
+            const item = raw as Record<string, unknown>;
+            if ('answer' in item || 'keywords' in item || 'text' in item || 'label' in item) {
+                return toSafeText(item);
+            }
+        }
+        return raw;
+    })();
+
+    return {
+        ...q,
+        question_text: toSafeText(q.question_text),
+        tags: safeTags,
+        options: safeOptions,
+        correct_answer: safeCorrectAnswer,
+    };
+};
+
 export default function QuestionBankPage() {
     const [questions, setQuestions] = useState<QuestionBank[]>([]);
     const [loading, setLoading] = useState(true);
@@ -24,22 +85,25 @@ export default function QuestionBankPage() {
     const [showEditor, setShowEditor] = useState(false);
     const [editingQuestion, setEditingQuestion] = useState<QuestionBank | null>(null);
     const [showImportModal, setShowImportModal] = useState(false);
+    const [currentPage, setCurrentPage] = useState(1);
+    const [pageSize, setPageSize] = useState(20);
 
-    const loadQuestions = async () => {
+    const loadQuestions = useCallback(async () => {
         try {
             setLoading(true);
             const data = await questionBankApi.list(filters);
-            setQuestions(data);
+            setQuestions(data.map(sanitizeQuestion));
+            setCurrentPage(1);
         } catch (error) {
             console.error('Failed to load questions:', error);
         } finally {
             setLoading(false);
         }
-    };
+    }, [filters]);
 
     useEffect(() => {
         loadQuestions();
-    }, [filters]);
+    }, [loadQuestions]);
 
     const handleCreate = () => {
         setEditingQuestion(null);
@@ -68,31 +132,6 @@ export default function QuestionBankPage() {
         await loadQuestions();
     };
 
-    const getQuestionTypeLabel = (type: QuestionBankType) => {
-        const labels: Record<QuestionBankType, string> = {
-            'multiple-choice': 'Opción Múltiple',
-            'true-false': 'Verdadero/Falso',
-            'short-answer': 'Respuesta Corta',
-            'essay': 'Ensayo',
-            'matching': 'Emparejamiento',
-            'ordering': 'Ordenar',
-            'fill-in-the-blanks': 'Completar',
-            'audio-response': 'Respuesta Audio',
-            'hotspot': 'Hotspot',
-            'code-lab': 'Código',
-        };
-        return labels[type] || type;
-    };
-
-    const getDifficultyColor = (difficulty?: string) => {
-        switch (difficulty) {
-            case 'easy': return 'bg-green-100 text-green-800';
-            case 'medium': return 'bg-yellow-100 text-yellow-800';
-            case 'hard': return 'bg-red-100 text-red-800';
-            default: return 'bg-gray-100 text-gray-800';
-        }
-    };
-
     return (
         <div className="min-h-screen bg-gray-50 dark:bg-gray-900">
             {/* Header */}
@@ -187,7 +226,7 @@ export default function QuestionBankPage() {
                             </label>
                             <select
                                 value={filters.question_type || ''}
-                                onChange={(e) => setFilters({ ...filters, question_type: e.target.value as QuestionBankType || undefined })}
+                                onChange={(e) => setFilters({ ...filters, question_type: (e.target.value || undefined) as QuestionBankFilters['question_type'] })}
                                 className="w-full px-3 py-2 border border-gray-300 dark:border-gray-600 rounded-lg focus:ring-2 focus:ring-blue-500 dark:bg-gray-700 dark:text-white"
                             >
                                 <option value="">Todos los tipos</option>
@@ -280,18 +319,107 @@ export default function QuestionBankPage() {
                             </button>
                         </div>
                     </div>
-                ) : (
+                ) : (() => {
-                    <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6">
+                    const totalPages = Math.ceil(questions.length / pageSize);
-                        {questions.map((question) => (
+                    const paginated = questions.slice((currentPage - 1) * pageSize, currentPage * pageSize);
-                            <QuestionBankCard
+                    return (
-                                key={question.id}
+                        <>
-                                question={question}
+                            {/* Page size + info */}
-                                onEdit={() => handleEdit(question)}
+                            <div className="flex items-center justify-between mb-4">
-                                onDelete={() => handleDelete(question.id)}
+                                <p className="text-sm text-gray-500 dark:text-gray-400">
-                            />
+                                    Mostrando {(currentPage - 1) * pageSize + 1}–{Math.min(currentPage * pageSize, questions.length)} de {questions.length} preguntas
-                        ))}
+                                </p>
-                    </div>
+                                <div className="flex items-center gap-2">
-                )}
+                                    <span className="text-sm text-gray-600 dark:text-gray-400">Por página:</span>
+                                    {[20, 50, 100].map((size) => (
+                                        <button
+                                            key={size}
+                                            onClick={() => { setPageSize(size); setCurrentPage(1); }}
+                                            className={`px-3 py-1 text-sm rounded-md border transition-colors ${
+                                                pageSize === size
+                                                    ? 'bg-blue-600 text-white border-blue-600'
+                                                    : 'border-gray-300 dark:border-gray-600 text-gray-700 dark:text-gray-300 hover:bg-gray-50 dark:hover:bg-gray-700'
+                                            }`}
+                                        >
+                                            {size}
+                                        </button>
+                                    ))}
+                                </div>
+                            </div>
+
+                            <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6">
+                                {paginated.map((question) => (
+                                    <QuestionBankCard
+                                        key={question.id}
+                                        question={question}
+                                        onEdit={() => handleEdit(question)}
+                                        onDelete={() => handleDelete(question.id)}
+                                    />
+                                ))}
+                            </div>
+
+                            {/* Pagination controls */}
+                            {totalPages > 1 && (
+                                <div className="flex items-center justify-center gap-2 mt-8">
+                                    <button
+                                        onClick={() => setCurrentPage(1)}
+                                        disabled={currentPage === 1}
+                                        className="px-3 py-1 text-sm rounded-md border border-gray-300 dark:border-gray-600 disabled:opacity-40 hover:bg-gray-50 dark:hover:bg-gray-700 disabled:cursor-not-allowed"
+                                    >
+                                        «
+                                    </button>
+                                    <button
+                                        onClick={() => setCurrentPage((p) => Math.max(1, p - 1))}
+                                        disabled={currentPage === 1}
+                                        className="px-3 py-1 text-sm rounded-md border border-gray-300 dark:border-gray-600 disabled:opacity-40 hover:bg-gray-50 dark:hover:bg-gray-700 disabled:cursor-not-allowed"
+                                    >
+                                        ‹
+                                    </button>
+
+                                    {Array.from({ length: totalPages }, (_, i) => i + 1)
+                                        .filter((p) => p === 1 || p === totalPages || Math.abs(p - currentPage) <= 2)
+                                        .reduce<(number | '...')[]>((acc, p, idx, arr) => {
+                                            if (idx > 0 && (p as number) - (arr[idx - 1] as number) > 1) acc.push('...');
+                                            acc.push(p);
+                                            return acc;
+                                        }, [])
+                                        .map((p, idx) =>
+                                            p === '...' ? (
+                                                <span key={`ellipsis-${idx}`} className="px-2 text-gray-400">…</span>
+                                            ) : (
+                                                <button
+                                                    key={p}
+                                                    onClick={() => setCurrentPage(p as number)}
+                                                    className={`px-3 py-1 text-sm rounded-md border transition-colors ${
+                                                        currentPage === p
+                                                            ? 'bg-blue-600 text-white border-blue-600'
+                                                            : 'border-gray-300 dark:border-gray-600 text-gray-700 dark:text-gray-300 hover:bg-gray-50 dark:hover:bg-gray-700'
+                                                    }`}
+                                                >
+                                                    {p}
+                                                </button>
+                                            )
+                                        )}
+
+                                    <button
+                                        onClick={() => setCurrentPage((p) => Math.min(totalPages, p + 1))}
+                                        disabled={currentPage === totalPages}
+                                        className="px-3 py-1 text-sm rounded-md border border-gray-300 dark:border-gray-600 disabled:opacity-40 hover:bg-gray-50 dark:hover:bg-gray-700 disabled:cursor-not-allowed"
+                                    >
+                                        ›
+                                    </button>
+                                    <button
+                                        onClick={() => setCurrentPage(totalPages)}
+                                        disabled={currentPage === totalPages}
+                                        className="px-3 py-1 text-sm rounded-md border border-gray-300 dark:border-gray-600 disabled:opacity-40 hover:bg-gray-50 dark:hover:bg-gray-700 disabled:cursor-not-allowed"
+                                    >
+                                        »
+                                    </button>
+                                </div>
+                            )}
+                        </>
+                    );
+                })()}
             </div>
 
             {/* Editor Modal */}

web/studio/src/components/QuestionBank/QuestionBankCard.tsx

@@ -12,8 +12,34 @@ interface QuestionBankCardProps {
 export default function QuestionBankCard({ question, onEdit, onDelete }: QuestionBankCardProps): React.JSX.Element {
     const [isPlaying, setIsPlaying] = useState(false);
     const [audio, setAudio] = useState<HTMLAudioElement | null>(null);
-    const safeQuestionText: React.ReactNode =
+
-        typeof question.question_text === 'string' ? question.question_text : '';
+    const toDisplayText = (value: any): string => {
+        if (value === null || value === undefined) return '';
+        if (typeof value === 'string' || typeof value === 'number' || typeof value === 'boolean') {
+            return String(value);
+        }
+        if (Array.isArray(value)) {
+            return value.map((v) => toDisplayText(v)).filter(Boolean).join(', ');
+        }
+        if (typeof value === 'object') {
+            if (typeof value.answer === 'string') return value.answer;
+            if (typeof value.text === 'string') return value.text;
+            if (typeof value.label === 'string') return value.label;
+            try {
+                return JSON.stringify(value);
+            } catch {
+                return '';
+            }
+        }
+        return '';
+    };
+
+    const safeSourceText = toDisplayText(question.source);
+    const safeDifficultyText = toDisplayText(question.difficulty);
+    const safeSkillAssessedText = toDisplayText(question.skill_assessed);
+    const safePointsText = toDisplayText(question.points);
+    const safeQuestionTypeText = toDisplayText(question.question_type);
+    const safeQuestionText = toDisplayText(question.question_text);
 
     const getQuestionTypeLabel = (type: string) => {
         const labels: Record<string, string> = {
@@ -41,7 +67,7 @@ export default function QuestionBankCard({ question, onEdit, onDelete }: Questio
     };
 
     const sourceBadge = (() => {
-        switch (question.source) {
+        switch (safeSourceText) {
             case 'imported-mysql':
             case 'sam-diagnostico':
                 return (
@@ -64,8 +90,8 @@ export default function QuestionBankCard({ question, onEdit, onDelete }: Questio
             case 'manual':
                 return <span className="text-xs text-gray-500 dark:text-gray-400">Manual</span>;
             default:
-                return question.source ? (
+                return safeSourceText ? (
-                    <span className="text-xs text-gray-500 dark:text-gray-400">{question.source}</span>
+                    <span className="text-xs text-gray-500 dark:text-gray-400">{safeSourceText}</span>
                 ) : null;
         }
     })();
@@ -104,14 +130,14 @@ export default function QuestionBankCard({ question, onEdit, onDelete }: Questio
                 <div className="flex-1">
                     <div className="flex items-center gap-2 mb-2 flex-wrap">
                         <span className="px-2 py-1 bg-blue-100 dark:bg-blue-900/30 text-blue-700 dark:text-blue-400 text-xs font-medium rounded">
-                            {getQuestionTypeLabel(question.question_type)}
+                            {getQuestionTypeLabel(safeQuestionTypeText)}
                         </span>
-                        <span className={`px-2 py-1 text-xs font-medium rounded ${getDifficultyColor(question.difficulty)}`}>
+                        <span className={`px-2 py-1 text-xs font-medium rounded ${getDifficultyColor(safeDifficultyText || undefined)}`}>
-                            {question.difficulty || 'Medium'}
+                            {safeDifficultyText || 'Medium'}
                         </span>
-                        {question.skill_assessed && (
+                        {safeSkillAssessedText && (
                             <span className="px-2 py-1 bg-purple-100 dark:bg-purple-900/30 text-purple-700 dark:text-purple-400 text-xs font-medium rounded capitalize">
-                                📊 {question.skill_assessed}
+                                📊 {safeSkillAssessedText}
                             </span>
                         )}
                     </div>
@@ -145,7 +171,7 @@ export default function QuestionBankCard({ question, onEdit, onDelete }: Questio
 
             {/* Question Text */}
             <p className="text-gray-900 dark:text-white font-medium mb-3 line-clamp-3">
-                {safeQuestionText as any}
+                {safeQuestionText}
             </p>
 
             {/* Matching Pairs Preview */}
@@ -163,9 +189,9 @@ export default function QuestionBankCard({ question, onEdit, onDelete }: Questio
                         
                         return pairs.slice(0, 3).map((pair: any, idx: number) => (
                             <div key={idx} className="text-xs bg-gray-50 dark:bg-gray-700/50 p-2 rounded flex items-center gap-2">
-                                <span className="flex-1 text-gray-700 dark:text-gray-300">{pair.left || pair[0]}</span>
+                                <span className="flex-1 text-gray-700 dark:text-gray-300">{toDisplayText(pair.left ?? pair[0])}</span>
                                 <span className="text-gray-400">→</span>
-                                <span className="flex-1 text-gray-600 dark:text-gray-400 line-clamp-1">{pair.right || pair[1]}</span>
+                                <span className="flex-1 text-gray-600 dark:text-gray-400 line-clamp-1">{toDisplayText(pair.right ?? pair[1])}</span>
                             </div>
                         ));
                     })()}
@@ -194,12 +220,12 @@ export default function QuestionBankCard({ question, onEdit, onDelete }: Questio
             {/* Options Preview */}
             {question.options && (
                 <div className="mb-3 space-y-1">
-                    {Array.isArray(question.options) && question.options.slice(0, 3).map((opt: string, idx: number) => (
+                    {Array.isArray(question.options) && question.options.slice(0, 3).map((opt: any, idx: number) => (
                         <div key={idx} className="text-xs text-gray-500 dark:text-gray-400 flex items-center gap-2">
                             <span className="w-4 h-4 rounded border border-gray-300 dark:border-gray-600 flex items-center justify-center text-[10px]">
                                 {String.fromCharCode(65 + idx)}
                             </span>
-                            <span className="line-clamp-1">{opt}</span>
+                            <span className="line-clamp-1">{toDisplayText(opt)}</span>
                         </div>
                     ))}
                     {Array.isArray(question.options) && question.options.length > 3 && (
@@ -212,7 +238,7 @@ export default function QuestionBankCard({ question, onEdit, onDelete }: Questio
             <div className="pt-3 border-t border-gray-200 dark:border-gray-700 flex items-center justify-between">
                 <div className="flex items-center gap-3">
                     <span className="text-xs font-medium text-gray-600 dark:text-gray-400">
-                        {question.points} pts
+                        {safePointsText || '0'} pts
                     </span>
                     {sourceBadge && <div className="flex items-center gap-1">{sourceBadge}</div>}
                 </div>

web/studio/src/components/QuestionBank/QuestionBankEditor.tsx

@@ -11,6 +11,20 @@ interface QuestionBankEditorProps {
 }
 
 export default function QuestionBankEditor({ question, onSuccess, onCancel }: QuestionBankEditorProps) {
+    const toDisplayText = (value: unknown): string => {
+        if (value === null || value === undefined) return '';
+        if (typeof value === 'string' || typeof value === 'number' || typeof value === 'boolean') return String(value);
+        if (Array.isArray(value)) return value.map((v) => toDisplayText(v)).filter(Boolean).join(', ');
+        if (typeof value === 'object') {
+            const obj = value as Record<string, unknown>;
+            if (typeof obj.answer === 'string') return obj.answer;
+            if (typeof obj.text === 'string') return obj.text;
+            if (typeof obj.label === 'string') return obj.label;
+            try { return JSON.stringify(obj); } catch { return ''; }
+        }
+        return '';
+    };
+
     const [formData, setFormData] = useState<CreateQuestionBankPayload>({
         question_text: question?.question_text || '',
         question_type: question?.question_type || 'multiple-choice',
@@ -34,7 +48,7 @@ export default function QuestionBankEditor({ question, onSuccess, onCancel }: Qu
     const [generatingAI, setGeneratingAI] = useState(false);
 
     const normalizedOptions = Array.isArray(formData.options)
-        ? (formData.options as string[])
+        ? (formData.options as unknown[]).map((opt) => toDisplayText(opt))
         : [];
 
     const handleSubmit = async (e: React.FormEvent) => {
@@ -476,10 +490,10 @@ export default function QuestionBankEditor({ question, onSuccess, onCancel }: Qu
                                     key={idx}
                                     className="px-3 py-1 bg-blue-100 dark:bg-blue-900/30 text-blue-700 dark:text-blue-400 rounded-full text-sm flex items-center gap-1"
                                 >
-                                    {tag}
+                                    {toDisplayText(tag)}
                                     <button
                                         type="button"
-                                        onClick={() => handleRemoveTag(tag)}
+                                        onClick={() => handleRemoveTag(toDisplayText(tag))}
                                         className="hover:text-blue-600"
                                     >
                                         <X className="w-3 h-3" />

web/studio/src/components/blocks/QuizBlock.tsx

@@ -25,6 +25,28 @@ export default function QuizBlock({ id, title, quizData, editMode, onChange }: Q
     const [userAnswers, setUserAnswers] = useState<Record<string, number[]>>({});
     const [submitted, setSubmitted] = useState(false);
 
+    const toDisplayText = (value: unknown): string => {
+        if (value === null || value === undefined) return '';
+        if (typeof value === 'string' || typeof value === 'number' || typeof value === 'boolean') {
+            return String(value);
+        }
+        if (Array.isArray(value)) {
+            return value.map((v) => toDisplayText(v)).filter(Boolean).join(', ');
+        }
+        if (typeof value === 'object') {
+            const obj = value as Record<string, unknown>;
+            if (typeof obj.answer === 'string') return obj.answer;
+            if (typeof obj.text === 'string') return obj.text;
+            if (typeof obj.label === 'string') return obj.label;
+            try {
+                return JSON.stringify(obj);
+            } catch {
+                return '';
+            }
+        }
+        return '';
+    };
+
     const questions = quizData.questions || [];
 
     const addQuestion = () => {
@@ -133,7 +155,7 @@ export default function QuizBlock({ id, title, quizData, editMode, onChange }: Q
                             <div className="space-y-3">
                                 <label className="text-[10px] font-black text-slate-400 dark:text-gray-500 uppercase tracking-widest pl-1">Inquiry Description</label>
                                 <textarea
-                                    value={q.question}
+                                    value={toDisplayText(q.question)}
                                     onChange={(e) => updateQuestion(idx, { question: e.target.value })}
                                     className="w-full bg-slate-50 dark:bg-black/40 border border-slate-200 dark:border-white/10 rounded-2xl p-6 text-lg font-black tracking-tight focus:ring-4 focus:ring-blue-500/10 focus:border-blue-500 transition-all placeholder:text-slate-300 resize-none shadow-inner h-24"
                                     placeholder="What is the core problem being evaluated?"
@@ -172,7 +194,7 @@ export default function QuizBlock({ id, title, quizData, editMode, onChange }: Q
                                                     )}
                                                 </div>
                                                 <input
-                                                    value={opt}
+                                                    value={toDisplayText(opt)}
                                                     onChange={(e) => {
                                                         const newOpts = [...q.options];
                                                         newOpts[oIdx] = e.target.value;
@@ -221,7 +243,7 @@ export default function QuizBlock({ id, title, quizData, editMode, onChange }: Q
                     {questions.map((q) => (
                         <div key={q.id} className="space-y-6 p-10 bg-white dark:bg-white/5 border border-slate-100 dark:border-white/5 rounded-[2.5rem] shadow-sm hover:shadow-xl transition-all duration-700 group/qitem relative overflow-hidden">
                             <div className="absolute top-0 right-0 w-32 h-32 bg-indigo-500/5 rounded-full blur-3xl -translate-y-1/2 translate-x-1/2 group-hover/qitem:bg-indigo-500/10 transition-colors"></div>
-                            <h4 className="font-black text-2xl text-slate-900 dark:text-white leading-tight uppercase tracking-tight relative z-10">{q.question}</h4>
+                            <h4 className="font-black text-2xl text-slate-900 dark:text-white leading-tight uppercase tracking-tight relative z-10">{toDisplayText(q.question)}</h4>
                             <div className="grid gap-3">
                                 {q.options && q.options.length > 0 ? (
                                     q.options.map((opt, oIdx) => {
@@ -246,7 +268,7 @@ export default function QuizBlock({ id, title, quizData, editMode, onChange }: Q
                                                 className={`p-6 rounded-2xl border transition-all text-left text-sm font-black uppercase tracking-tight relative overflow-hidden group/optans ${style}`}
                                             >
                                                 <div className="flex items-center justify-between relative z-10">
-                                                    <span>{opt}</span>
+                                                    <span>{toDisplayText(opt)}</span>
                                                     {submitted ? (
                                                         <div className="flex items-center gap-2">
                                                             {isActuallyCorrect && <span className="text-green-600 dark:text-green-400"><CheckCircle2 size={18} /></span>}

web/studio/src/lib/api.ts

@@ -1324,19 +1324,98 @@ export interface UpdateQuestionBankPayload {
     audio_text?: string;
 }
 
+const toSafeQuestionBankText = (value: unknown): string => {
+    if (value === null || value === undefined) return '';
+    if (typeof value === 'string' || typeof value === 'number' || typeof value === 'boolean') {
+        return String(value);
+    }
+    if (Array.isArray(value)) {
+        return value.map((v) => toSafeQuestionBankText(v)).filter(Boolean).join(', ');
+    }
+    if (typeof value === 'object') {
+        const obj = value as Record<string, unknown>;
+        if (typeof obj.answer === 'string') return obj.answer;
+        if (typeof obj.text === 'string') return obj.text;
+        if (typeof obj.label === 'string') return obj.label;
+        try {
+            return JSON.stringify(obj);
+        } catch {
+            return '';
+        }
+    }
+    return '';
+};
+
+const normalizeQuestionBank = (q: QuestionBank): QuestionBank => {
+    const safeTags = Array.isArray(q.tags)
+        ? q.tags.map((tag) => toSafeQuestionBankText(tag)).filter(Boolean)
+        : [];
+
+    const safeOptions = Array.isArray(q.options)
+        ? q.options.map((opt) => toSafeQuestionBankText(opt))
+        : q.options;
+
+    const safeCorrectAnswer = (() => {
+        const raw = q.correct_answer;
+        if (Array.isArray(raw)) {
+            return raw.map((item) => toSafeQuestionBankText(item));
+        }
+        if (raw && typeof raw === 'object') {
+            const obj = raw as Record<string, unknown>;
+            if (Array.isArray(obj.pairs)) {
+                return obj.pairs.map((pair) => {
+                    if (pair && typeof pair === 'object') {
+                        const pairObj = pair as Record<string, unknown>;
+                        return {
+                            left: toSafeQuestionBankText(pairObj.left ?? pairObj[0]),
+                            right: toSafeQuestionBankText(pairObj.right ?? pairObj[1]),
+                        };
+                    }
+                    return {
+                        left: toSafeQuestionBankText(pair),
+                        right: '',
+                    };
+                });
+            }
+            if ('answer' in obj || 'keywords' in obj || 'text' in obj || 'label' in obj) {
+                return toSafeQuestionBankText(obj);
+            }
+        }
+        return raw;
+    })();
+
+    return {
+        ...q,
+        question_text: toSafeQuestionBankText(q.question_text),
+        tags: safeTags,
+        options: safeOptions,
+        correct_answer: safeCorrectAnswer,
+    };
+};
+
 export const questionBankApi = {
-    list: (filters?: QuestionBankFilters): Promise<QuestionBank[]> =>
+    list: async (filters?: QuestionBankFilters): Promise<QuestionBank[]> => {
-        apiFetch('/question-bank', { method: 'GET', query: filters as Record<string, string | number | boolean | undefined | null> }, false),
+        const questions = await apiFetch('/question-bank', { method: 'GET', query: filters as Record<string, string | number | boolean | undefined | null> }, false);
-    get: (id: string): Promise<QuestionBank> =>
+        return (questions as QuestionBank[]).map(normalizeQuestionBank);
-        apiFetch(`/question-bank/${id}`, {}, false),
+    },
-    create: (payload: CreateQuestionBankPayload): Promise<QuestionBank> =>
+    get: async (id: string): Promise<QuestionBank> => {
-        apiFetch('/question-bank', { method: 'POST', body: JSON.stringify(payload) }, false),
+        const question = await apiFetch(`/question-bank/${id}`, {}, false);
-    update: (id: string, payload: UpdateQuestionBankPayload): Promise<QuestionBank> =>
+        return normalizeQuestionBank(question as QuestionBank);
-        apiFetch(`/question-bank/${id}`, { method: 'PUT', body: JSON.stringify(payload) }, false),
+    },
+    create: async (payload: CreateQuestionBankPayload): Promise<QuestionBank> => {
+        const question = await apiFetch('/question-bank', { method: 'POST', body: JSON.stringify(payload) }, false);
+        return normalizeQuestionBank(question as QuestionBank);
+    },
+    update: async (id: string, payload: UpdateQuestionBankPayload): Promise<QuestionBank> => {
+        const question = await apiFetch(`/question-bank/${id}`, { method: 'PUT', body: JSON.stringify(payload) }, false);
+        return normalizeQuestionBank(question as QuestionBank);
+    },
     delete: (id: string): Promise<void> =>
         apiFetch(`/question-bank/${id}`, { method: 'DELETE' }, false),
-    importFromMySQL: (courseId?: number, questionIds?: number[], importAll?: boolean): Promise<QuestionBank[]> =>
+    importFromMySQL: async (courseId?: number, questionIds?: number[], importAll?: boolean): Promise<QuestionBank[]> => {
-        apiFetch('/question-bank/import-mysql', { method: 'POST', body: JSON.stringify({ mysql_course_id: courseId, question_ids: questionIds, import_all: importAll }) }, false),
+        const questions = await apiFetch('/question-bank/import-mysql', { method: 'POST', body: JSON.stringify({ mysql_course_id: courseId, question_ids: questionIds, import_all: importAll }) }, false);
+        return (questions as QuestionBank[]).map(normalizeQuestionBank);
+    },
     getMySQLPlans: async (): Promise<MySqlPlan[]> => {
         const plans = (await apiFetch('/question-bank/mysql-plans', {}, false)) as MySqlPlanRaw[];
         return plans.reduce((acc: MySqlPlan[], p: MySqlPlanRaw) => {