refactor: Replace Rollup with Vite (#2656)

This is a high risk change: every byte the card ships is emitted by a
different bundler, minified by a different minifier, and every
stylesheet is compiled by a different sass. The intent is that the
card's behaviour is unchanged.

**Significant development win**: Build time drops from 24s to 1.1s 🎉 

Also adds a test suite ('dist') that runs against the built bundle.

scripts/svg-path-plugin.js

@@ -1,16 +1,16 @@
 import { readFileSync } from 'node:fs';
 
 /**
- * Rollup/Vite plugin: importing an SVG yields `{ path, viewBox }` extracted at
- * build time, the shape a Home Assistant custom iconset serves. The SVG must
- * be a single-path icon.
+ * Vite plugin: importing an SVG yields `{ path, viewBox }` extracted at build
+ * time, the shape a Home Assistant custom iconset serves. The SVG must be a
+ * single-path icon.
  *
- * @type {() => import('rollup').Plugin}
+ * @type {() => import('vite').Plugin}
  */
 export const svgPath = () => ({
   name: 'svg-path',
 
-  // Vite: run before its builtin asset handling.
+  // Run before Vite's builtin asset handling.
   enforce: 'pre',
 
   load(id) {