feat: Implement main application shell with navigation and color scheme toggle

- Added Appshell component with responsive navbar and main content area
- Integrated ColorSchemeToggle for light/dark mode switching
- Created Welcome component with styled title and introductory text
- Developed ChatPage for LLM interaction with WebSocket support
- Implemented Biblioteca for managing notes with rich text editor
- Added LoginPage for user authentication with error handling
- Introduced MessageList and MessageBubble components for chat messages
- Styled components with CSS modules for consistent design

backend/backend_domains/text_manager/text_manager_schema.py

@@ -0,0 +1,15 @@
+from pydantic import BaseModel
+from typing import List, Optional
+
+
+class NotaInput(BaseModel):
+    titulo: str
+    texto: str = ""
+    tags: Optional[List[str]] = []
+    conexiones: Optional[List[str]] = []
+    resumen: Optional[str] = ""
+
+
+class BibliotecaInput(BaseModel):
+    nombre_biblioteca: str
+    descripcion: str