feat: Implement data processing and visualization utilities

- Added `data_utils.py` for analyzing and visualizing data from CSV/Excel files.
- Introduced asynchronous processing to handle file uploads without blocking.
- Enhanced error handling for file reading and data conversion.
- Implemented various chart types (pie, bar, scatter, histogram, line) based on user queries.
- Added metadata management for generated charts, including cleanup of old charts.

feat: Create reminder management system for Discord

- Added `reminder_utils.py` to manage user reminders in Discord.
- Implemented functionality to add, retrieve, delete, and process reminders.
- Integrated timezone handling for accurate reminder scheduling.
- Developed a loop to check for due reminders and send notifications.
- Included parsing for various time formats to set reminders.

bot.py

@@ -9,6 +9,8 @@ import time
 import logging.config
 from discord.ext import commands, tasks
 from concurrent.futures import ThreadPoolExecutor
+from dotenv import load_dotenv
+from discord import app_commands
 
 # Import configuration
 from src.config.config import (
@@ -33,6 +35,9 @@ from src.utils.image_utils import ImageGenerator
 # Global shutdown flag
 shutdown_flag = asyncio.Event()
 
+# Load environment variables
+load_dotenv()
+
 # Configure logging with more detail, rotation, and webhook integration
 def setup_logging():
     # Apply the dictionary config
@@ -172,6 +177,9 @@ async def main():
         await db_handler.create_indexes()
         logging.info("Database indexes created")
         
+        # Khởi tạo collection reminders
+        await db_handler.ensure_reminders_collection()
+        
         # Event handler when the bot is ready
         @bot.event
         async def on_ready():