Add v2 Text typography primitive

Implement the first v2 typography component from the Probo Radix UI
Figma: a Text primitive rendering a single span with size, weight,
align, color, and highContrast variants (color x highContrast
resolves to the sand/gold/red/green/amber/sky text step 11 or 12),
plus a paired TextSkeleton. Styling is tailwind-variants only, with
the scale shared through a variants module per the kit guides.

Stand up a theme-isolated v2 Storybook (.storybook-v2) loading the
v2 theme with a light/dark toggle, since v1 and v2 cannot share one
Tailwind build; the v1 build now excludes src/v2.

Signed-off-by: Émile Ré <emile@probo.com>

packages/ui/.storybook-v2/preview.tsx

@@ -0,0 +1,59 @@
+// Copyright (c) 2025-2026 Probo Inc <hello@probo.com>.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+import type { Preview } from "@storybook/react";
+import { useEffect } from "react";
+
+import "./preview.css";
+
+const preview: Preview = {
+  parameters: {
+    controls: {
+      matchers: {
+        color: /(background|color)$/i,
+        date: /Date$/i,
+      },
+    },
+  },
+  globalTypes: {
+    theme: {
+      description: "v2 color theme",
+      defaultValue: "light",
+      toolbar: {
+        title: "Theme",
+        icon: "circlehollow",
+        items: [
+          { value: "light", title: "Light" },
+          { value: "dark", title: "Dark" },
+        ],
+        dynamicTitle: true,
+      },
+    },
+  },
+  decorators: [
+    (Story, context) => {
+      const isDark = context.globals.theme === "dark";
+      useEffect(() => {
+        document.documentElement.classList.toggle("dark", isDark);
+      }, [isDark]);
+      return (
+        <div className="min-h-screen bg-sand-1 p-8 text-sand-12">
+          <Story />
+        </div>
+      );
+    },
+  ],
+};
+
+export default preview;