Refactor project structure and implement new features

- Removed unused security module and updated import paths.
- Enhanced OpenAI client with streaming capabilities for chat completions.
- Added new backend API endpoints for health check (ping).
- Established a new FastAPI application with CORS configuration.
- Created a new Appshell component for the frontend with navigation links.
- Integrated SVG icons and improved styling for the Appshell component.
- Implemented memory management for conversation history using PostgreSQL.
- Developed abstract classes for AI agents and models, with OpenAI integration.
- Added encryption utilities for secure data handling.

src/Llms/Memory/Base_MemoryConv.py

@@ -0,0 +1,36 @@
+from abc import ABC, abstractmethod
+from typing import Literal
+
+class MemoryConvABC(ABC):
+    """
+    Interfaz abstracta para memorias de conversación multi-turno.
+    """
+
+    def __init__(self, k: int = 10):
+        """
+        :param k: Número máximo de turnos (pares user/assistant) a retornar.
+        """
+        self.k = k
+
+    @abstractmethod
+    def guardar_turno(self, rol: Literal["user", "assistant"], contenido: str) -> None:
+        """
+        Guarda un mensaje de un turno de conversación.
+        Se guarda secuencialmente y se asume que el orden es respetado.
+        """
+        pass
+
+    @abstractmethod
+    def cargar_historial_chat(self) -> list[dict]:
+        """
+        Devuelve los últimos `k*2` mensajes como lista de dicts tipo chat:
+        [{"role": "user", "content": "..."}, {"role": "assistant", "content": "..."}]
+        """
+        pass
+
+    @abstractmethod
+    def limpiar(self) -> None:
+        """
+        Limpia completamente la memoria.
+        """
+        pass