feat: Implement Walmart scraper and integrate with existing architecture

- Added Walmart scraper to scrape product data from Walmart.com, including category pages and product details.
- Introduced a stealth browser module to handle bot protection and improve scraping reliability.
- Created a SQLite database for tracking product history, price changes, stock events, and user favorites.
- Developed a Discord bot for user interaction, allowing location setting and stock checking at local stores.
- Implemented a favorites system to manage priority products and categories with custom notification settings.
- Added news aggregation module to fetch and analyze Pokemon TCG news from various sources.
- Created tools for API discovery and monitoring, including a backend monitor for detecting new products.
- Added unit tests for database operations, product filtering, and API endpoints to ensure functionality.
- Enhanced existing modules with improved error handling and logging for better maintainability.

docs/NOTES.md

@@ -0,0 +1,13 @@
+# Pokemon Stock Monitor - Notes
+
+## Bot Detection / CAPTCHA Log
+
+| Date | Time | Site | Notes |
+|------|------|------|-------|
+| 2026-03-25 | ~10:30 AM | PokemonCenter | CAPTCHAs appeared, bot protection triggered |
+
+## Tips
+- Pokemon Center uses Imperva bot protection
+- CAPTCHAs more likely during high traffic (product drops)
+- Using Chrome extension with real browser avoids most detection
+- If blocked, clear cookies and wait before retrying