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/_travel.scss

@@ -1,5 +1,5 @@
-@use 'shared/_colors'as c;
-@use 'shared/_utils'as u;
+@use 'shared/_colors' as c;
+@use 'shared/_utils' as u;
 
 .weather-display .main.travel {
 	&.main {
@@ -8,14 +8,11 @@
 		.column-headers {
 			background-color: c.$column-header;
 			height: 20px;
-			position: absolute;
-			width: 100%;
-		}
-
-		.column-headers {
 			position: sticky;
 			top: 0px;
+			width: 100%;
 			z-index: 5;
+			overflow: hidden; // prevent thin gaps between header and content
 
 			div {
 				display: inline-block;
@@ -100,4 +97,4 @@
 			}
 		}
 	}
-}
+}