feat(ui): enable storybook snapshot tests

- adds a process-compose namespace for running `storybook` and `luakit` together to replicate the `webkit`-based rendering that happens inside of `webview`
- adds some helper scripts for running storybook tests and updating snapshots, with documentation in the README.
- adds a `clan-app-ui-storybook` package which builds and tests the storybook, checking for rendering changes

Currently, we’re only doing markup-based snapshot tests. We’re also using headless chromium for the tests by default as I couldn't get webkit to work in the nix build.

As we’re only markup-based for the time being, this should be ok. But eventually I'd like to get it working with webkit.

pkgs/clan-app/ui/eslint.config.mjs

@@ -2,6 +2,7 @@ import eslint from "@eslint/js";
 import tseslint from "typescript-eslint";
 import tailwind from "eslint-plugin-tailwindcss";
 import pluginQuery from "@tanstack/eslint-plugin-query";
+import { globalIgnores } from "eslint/config";
 
 const config = tseslint.config(
   eslint.configs.recommended,
@@ -9,6 +10,7 @@ const config = tseslint.config(
   ...tseslint.configs.strict,
   ...tseslint.configs.stylistic,
   ...tailwind.configs["flat/recommended"],
+  globalIgnores(["src/types/index.d.ts"]),
   {
     rules: {
       "tailwindcss/no-contradicting-classname": [