refactor(components): convert const to reactive where appropriate

- Inline class assignments to avoid script-level clutter
- Ignore a11y-missing-attribute instead of redundant href

src/components/Tabs/TabContent.svelte

@@ -6,7 +6,6 @@
   import { getContext } from 'svelte';
   import { cx } from '../../lib';
 
-  const _class = cx('--tab-content', className);
   const id = Math.random();
   const { selectedContent, addContent } = getContext('Tabs');
 
@@ -15,6 +14,6 @@
   $: selected = $selectedContent === id;
 </script>
 
-<div class={_class} aria-hidden={!selected} hidden={!selected} {style}>
+<div aria-hidden={!selected} hidden={!selected} class={cx('--tab-content', className)} {style}>
   <slot />
 </div>