Add responsive scaling; improve scanlines and Mobile Safari support

- Replace CSS zoom with CSS transform scaling for better mobile compatibility
- Implement wrapper-based scaling approach that includes both content and navigation bar
- Replace Almanac layout with CSS Grid for better cross-browser layout
- Greatly improve scanline algorithm to handle a wide variety of displays
- Add setting to override automatic scanlines to user-specified scale factor
- Remove scanline scaling debug functions
- Refactor settings module: initialize settings upfront and improve change handler declarations
- Enhance scanline SCSS with repeating-linear-gradient for better performance
- Add app icon for iOS/iPadOS
- Add 'fullscreen' event listener
- De-bounce 'resize' event listener
- Add 'orientationchange' event listener
- Implement three resize scaling algorithms:
  - Baseline (when no scaling is needed, like on the index page)
  - Mobile scaling (except Mobile Safari kiosk mode)
  - Mobile Safari kiosk mode (using manual offset calculations)
  - Standard fullscreen/kiosk mode (using CSS centering)

server/styles/scss/_weather-display.scss

@@ -94,11 +94,13 @@
 
 		&.has-scroll {
 			width: 640px;
+			margin-top: 0;
 			height: 310px;
 			overflow: hidden;
 
 			&.no-header {
 				height: 400px;
+				margin-top: 0; // Reset for no-header case since the gap issue is header-related
 			}
 		}