feat: Add dashboard support and enhance Discord webhook functionality

- Updated docker-compose.yml to expose dashboard on port 8080.
- Enhanced main.py with timezone database caching and improved state management.
- Introduced a minimal dashboard using Flask to display webhook status and notifications.
- Added templates.json for customizable embed messages in Discord notifications.
- Created templates.py for loading and saving notification templates.
- Implemented tests for dashboard rendering and main functionality.
- Added requirements for Flask and tzdata to support new features.
- Included test cases for timezone handling and template management.

.gitignore

@@ -1,4 +1,5 @@
 .github/copilot-instructions.md
+.github/instructions/*
 # Byte-compiled / optimized / DLL files
 __pycache__/
 *.py[cod]