Add a Vite plugin to auto-prefix -webkit-user-select so it's not so often forgotten (#4288)

* Add a Vite plugin to auto-prefix -webkit-user-select so it's not so often forgotten

* Enforce a property boundary on the left

frontend/src/components/Editor.svelte

@@ -233,7 +233,6 @@
 		height: 100%;
 		background: var(--color-2-mildblack);
 		overscroll-behavior: none;
-		-webkit-user-select: none; // Still required by Safari as of 2025
 		user-select: none;
 	}
 

frontend/src/components/floating-menus/Dialog.svelte

@@ -136,7 +136,6 @@
 			}
 
 			.text-label.multiline {
-				-webkit-user-select: text; // Still required by Safari as of 2026
 				user-select: text;
 			}
 

frontend/src/components/panels/Layers.svelte

@@ -884,7 +884,6 @@
 						width: 100%;
 
 						&:disabled {
-							-webkit-user-select: none; // Still required by Safari as of 2025
 							user-select: none;
 							// Workaround for `user-select: none` not working on <input> elements
 							pointer-events: none;

frontend/src/components/views/Graph.svelte

@@ -952,7 +952,6 @@
 				&.faded:hover {
 					z-index: 2;
 					opacity: 1;
-					-webkit-user-select: text;
 					user-select: text;
 					transition:
 						opacity 0.2s,