Implement calendar display application

Built a full-featured smart display app with Flask backend and responsive frontend.

Features:
- Real-time clock display
- Weather integration (OpenWeatherMap API) for Hamilton, NZ
- Google Calendar integration (placeholder, needs credentials)
- Rotating background images from local directory
- Dad jokes display (icanhazdadjoke API)

Technical stack:
- Backend: Python Flask with API endpoints
- Frontend: HTML/CSS/JavaScript with auto-updating data
- Caching system to avoid API rate limits
- Responsive design for various screen sizes

Deployment ready for Raspberry Pi with systemd service and Chromium kiosk mode setup instructions.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

config.py

@@ -0,0 +1,30 @@
+import os
+from dotenv import load_dotenv
+
+# Load environment variables
+load_dotenv()
+
+class Config:
+    # Flask settings
+    SECRET_KEY = os.getenv('FLASK_SECRET_KEY', 'dev-secret-key-change-in-production')
+
+    # OpenWeatherMap API settings
+    OPENWEATHER_API_KEY = os.getenv('OPENWEATHER_API_KEY', '')
+    WEATHER_LOCATION = os.getenv('WEATHER_LOCATION', 'Hamilton,NZ')
+    WEATHER_LAT = float(os.getenv('WEATHER_LAT', '-37.7870'))
+    WEATHER_LON = float(os.getenv('WEATHER_LON', '175.2793'))
+    WEATHER_UNITS = 'metric'  # Use Celsius
+
+    # Google Calendar settings
+    GOOGLE_CALENDAR_ID = os.getenv('GOOGLE_CALENDAR_ID', '')
+    CALENDAR_DAYS_AHEAD = int(os.getenv('CALENDAR_DAYS_AHEAD', '7'))
+
+    # Update intervals (in seconds)
+    IMAGE_ROTATION_INTERVAL = int(os.getenv('IMAGE_ROTATION_INTERVAL', '300'))  # 5 minutes
+    WEATHER_UPDATE_INTERVAL = int(os.getenv('WEATHER_UPDATE_INTERVAL', '900'))  # 15 minutes
+    CALENDAR_UPDATE_INTERVAL = int(os.getenv('CALENDAR_UPDATE_INTERVAL', '300'))  # 5 minutes
+    JOKE_UPDATE_INTERVAL = int(os.getenv('JOKE_UPDATE_INTERVAL', '3600'))  # 1 hour
+
+    # Directories
+    BACKGROUNDS_DIR = os.path.join('static', 'backgrounds')
+    CREDENTIALS_DIR = 'credentials'