feat: Complete sprint 2 tasks

- Upgrade Python to 3.11 and update dependencies.
- Refactor main.py to isolate business logic.
- Fix bugs in flow_engine.py and printer.py.
- Improve database connection handling.
- Standardize error handling.
- Verify secret management.

bot/modules/message_handler.py

@@ -0,0 +1,57 @@
+# bot/modules/message_handler.py
+# This module handles the processing of text and voice messages.
+
+import logging
+import os
+from telegram import Update
+from telegram.ext import ContextTypes
+
+from bot.modules.transcription import transcribe_audio
+from bot.modules.dispatcher import send_step_message
+
+logger = logging.getLogger(__name__)
+
+async def text_and_voice_handler(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
+    """Handles text and voice messages for the flow engine."""
+    user_id = update.effective_user.id
+    flow_engine = context.bot_data["flow_engine"]
+
+    state = flow_engine.get_conversation_state(user_id)
+    if not state:
+        return
+
+    user_response = update.message.text
+    if update.message.voice:
+        voice = update.message.voice
+        temp_dir = 'temp_files'
+        os.makedirs(temp_dir, exist_ok=True)
+        file_path = os.path.join(temp_dir, f"{voice.file_id}.ogg")
+
+        try:
+            voice_file = await context.bot.get_file(voice.file_id)
+            await voice_file.download_to_drive(file_path)
+            logger.info(f"Voice message saved to {file_path}")
+
+            user_response = transcribe_audio(file_path)
+            logger.info(f"Transcription result: '{user_response}'")
+
+        except Exception as e:
+            logger.error(f"Error during voice transcription: {e}")
+            user_response = "Error al procesar el mensaje de voz."
+        finally:
+            if os.path.exists(file_path):
+                os.remove(file_path)
+
+    result = flow_engine.handle_response(user_id, user_response)
+
+    if result["status"] == "in_progress":
+        await send_step_message(update, result["step"])
+    elif result["status"] == "complete":
+        if "sales_pitch" in result:
+            await update.message.reply_text(result["sales_pitch"])
+        elif "nfc_tag" in result:
+            await update.message.reply_text(result["nfc_tag"], parse_mode='Markdown')
+        else:
+            await update.message.reply_text("Gracias por completar el flujo.")
+    elif result["status"] == "error":
+        await update.message.reply_text(result["message"])