chore(storybook): install and configure Storybook 10 with svelte-vite

.storybook/main.ts

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+import type { StorybookConfig } from '@storybook/sveltekit';
+
+const config: StorybookConfig = {
+  "stories": [
+    "../src/**/*.mdx",
+    "../src/**/*.stories.@(js|ts|svelte)"
+  ],
+  "addons": [
+    "@storybook/addon-svelte-csf",
+    "@chromatic-com/storybook",
+    "@storybook/addon-vitest",
+    "@storybook/addon-a11y",
+    "@storybook/addon-docs"
+  ],
+  "framework": "@storybook/sveltekit"
+};
+export default config;

.storybook/preview.ts

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+import type { Preview } from '@storybook/sveltekit'
+
+const preview: Preview = {
+  parameters: {
+    controls: {
+      matchers: {
+       color: /(background|color)$/i,
+       date: /Date$/i,
+      },
+    },
+
+    a11y: {
+      // 'todo' - show a11y violations in the test UI only
+      // 'error' - fail CI on a11y violations
+      // 'off' - skip a11y checks entirely
+      test: 'todo'
+    }
+  },
+};
+
+export default preview;

.storybook/vitest.setup.ts

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+import * as a11yAddonAnnotations from "@storybook/addon-a11y/preview";
+import { setProjectAnnotations } from '@storybook/sveltekit';
+import * as projectAnnotations from './preview';
+
+// This is an important step to apply the right configuration when testing your stories.
+// More info at: https://storybook.js.org/docs/api/portable-stories/portable-stories-vitest#setprojectannotations
+setProjectAnnotations([a11yAddonAnnotations, projectAnnotations]);