Update runtime ports and deployment defaults.

Switch backend/frontend to ports 8074/8075 and align Docker, CORS, frontend API base URL, and docs so deployment uses the new endpoints consistently.

docker-compose.yml

@@ -6,13 +6,13 @@ services:
       - ./backend/.env
     environment:
       DATABASE_URL: postgresql+psycopg://genexamenes:genexamenes@db:5432/genexamenes
-      # Sobrescribe backend/.env si aún tiene el puerto 3000 del frontend antiguo.
-      ALLOWED_ORIGINS: http://localhost:5173,http://localhost:3000
+      # Sobrescribe backend/.env con el puerto actual del frontend.
+      ALLOWED_ORIGINS: http://localhost:8075
       LLM_BASE_URL: 
       LLM_MODEL: qwen3.5:35b
       LLM_TIMEOUT_SECONDS: "180"
     ports:
-      - "8000:8000"
+      - "8074:8074"
     depends_on:
       db:
         condition: service_healthy
@@ -24,10 +24,10 @@ services:
     build:
       context: ./frontend
       args:
-        VITE_API_URL: ${VITE_API_URL:-http://localhost:8000}
+        VITE_API_URL: ${VITE_API_URL:-http://localhost:8074}
         VITE_GOOGLE_CLIENT_ID: ${VITE_GOOGLE_CLIENT_ID:-}
     ports:
-      - "5173:80"
+      - "8075:80"
     depends_on:
       - backend
     restart: unless-stopped