feat: Implement remote printing and sales RAG flow

Implement the first two items from the product roadmap:

1.  **Remote Printing Service:**
    *   Create a new `printer.py` module to handle sending files via SMTP and checking status via IMAP.
    *   Add a document handler in `main.py` to allow admin users to send files to the bot for printing.
    *   Add a `/check_print_status` command for admins to monitor the print job status.
    *   Add SMTP/IMAP configuration variables to `config.py` and `.env.example`.

2.  **Sales RAG Flow:**
    *   Implement a `sales_rag.py` module to generate personalized sales pitches.
    *   The sales flow uses a Retrieval-Augmented Generation (RAG) approach, retrieving relevant services from `services.json` to create a detailed prompt for the LLM.
    *   The existing `flow_engine.py` is modified to trigger the sales pitch generation upon completion of the `client_sales_funnel` flow.
    *   Update `main.py` to handle the flow engine's responses and send the generated pitch to the user.
    *   Update `client_sales_funnel.json` to be triggered by a button in the client menu.

talia_bot/config.py

@@ -46,3 +46,10 @@ CALENDLY_LINK = os.getenv("CALENDLY_LINK", "https://calendly.com/user/appointmen
 
 # Zona horaria por defecto para el manejo de fechas y horas
 TIMEZONE = os.getenv("TIMEZONE", "America/Mexico_City")
+
+# --- PRINT SERVICE ---
+SMTP_SERVER = os.getenv("SMTP_SERVER")
+SMTP_PORT = os.getenv("SMTP_PORT")
+SMTP_USER = os.getenv("SMTP_USER")
+SMTP_PASS = os.getenv("SMTP_PASS")
+IMAP_SERVER = os.getenv("IMAP_SERVER")