Add WCAG 2.1 Level AA accessibility across all components

src/lib/components/ToggleSwitch.svelte

@@ -4,9 +4,10 @@
   interface Props {
     checked: boolean;
     onchange?: (value: boolean) => void;
+    label?: string;
   }
 
-  let { checked = $bindable(), onchange }: Props = $props();
+  let { checked = $bindable(), onchange, label = "Toggle" }: Props = $props();
 
   function toggle() {
     checked = !checked;
@@ -17,10 +18,10 @@
 <button
   type="button"
   role="switch"
-  aria-label="Toggle"
+  aria-label={label}
   aria-checked={checked}
   class="relative inline-flex h-[24px] w-[48px] shrink-0 cursor-pointer rounded-full
-         transition-colors duration-200 ease-in-out focus:outline-none"
+         transition-colors duration-200 ease-in-out"
   style="background: {checked ? $config.accent_color : '#1a1a1a'};"
   onclick={toggle}
 >