chore(ui): refactor workspace to monorepo (#70)

## Summary by Sourcery

Refactor the UI project structure into a pnpm monorepo packages layout
and align tooling and automation with the new paths.

Enhancements:
- Reorganize the UI app from the root ui directory into packages/ui
within a pnpm workspace.
- Update pnpm workspace configuration to include all packages under
packages/*.
- Adjust paths in changeset configuration so the @dropout/ui package
resolves from packages/ui.

Build:
- Update pre-commit configuration paths and arguments to reflect the new
UI location and normalize hook argument formatting.
- Update Dependabot configuration so npm updates target /packages/ui
instead of /ui.

CI:
- Update GitHub Actions workflows to watch packages/** instead of ui/**
and to run frontend tasks from packages/ui.
- Update pnpm cache dependency paths in workflows to use the root
pnpm-lock.yaml.
- Simplify frontend install steps in test workflows to run from the
repository root.

Chores:
- Add a new index.html under packages/ui and remove the old
ui/index.html to match the new project layout.

1 files changed, 47 insertions, 0 deletions

diff --git a/packages/ui/README.md b/packages/ui/README.md
new file mode 100644
index 0000000..a45e2a0
--- /dev/null
+++ b/packages/ui/README.md
@@ -0,0 +1,47 @@
+# Svelte + TS + Vite
+
+This template should help get you started developing with Svelte and TypeScript in Vite.
+
+## Recommended IDE Setup
+
+[VS Code](https://code.visualstudio.com/) + [Svelte](https://marketplace.visualstudio.com/items?itemName=svelte.svelte-vscode).
+
+## Need an official Svelte framework?
+
+Check out [SvelteKit](https://github.com/sveltejs/kit#readme), which is also powered by Vite. Deploy anywhere with its serverless-first approach and adapt to various platforms, with out of the box support for TypeScript, SCSS, and Less, and easily-added support for mdsvex, GraphQL, PostCSS, Tailwind CSS, and more.
+
+## Technical considerations
+
+**Why use this over SvelteKit?**
+
+- It brings its own routing solution which might not be preferable for some users.
+- It is first and foremost a framework that just happens to use Vite under the hood, not a Vite app.
+
+This template contains as little as possible to get started with Vite + TypeScript + Svelte, while taking into account the developer experience with regards to HMR and intellisense. It demonstrates capabilities on par with the other `create-vite` templates and is a good starting point for beginners dipping their toes into a Vite + Svelte project.
+
+Should you later need the extended capabilities and extensibility provided by SvelteKit, the template has been structured similarly to SvelteKit so that it is easy to migrate.
+
+**Why `global.d.ts` instead of `compilerOptions.types` inside `jsconfig.json` or `tsconfig.json`?**
+
+Setting `compilerOptions.types` shuts out all other types not explicitly listed in the configuration. Using triple-slash references keeps the default TypeScript setting of accepting type information from the entire workspace, while also adding `svelte` and `vite/client` type information.
+
+**Why include `.vscode/extensions.json`?**
+
+Other templates indirectly recommend extensions via the README, but this file allows VS Code to prompt the user to install the recommended extension upon opening the project.
+
+**Why enable `allowJs` in the TS template?**
+
+While `allowJs: false` would indeed prevent the use of `.js` files in the project, it does not prevent the use of JavaScript syntax in `.svelte` files. In addition, it would force `checkJs: false`, bringing the worst of both worlds: not being able to guarantee the entire codebase is TypeScript, and also having worse typechecking for the existing JavaScript. In addition, there are valid use cases in which a mixed codebase may be relevant.
+
+**Why is HMR not preserving my local component state?**
+
+HMR state preservation comes with a number of gotchas! It has been disabled by default in both `svelte-hmr` and `@sveltejs/vite-plugin-svelte` due to its often surprising behavior. You can read the details [here](https://github.com/rixo/svelte-hmr#svelte-hmr).
+
+If you have state that's important to retain within a component, consider creating an external store which would not be replaced by HMR.
+
+```ts
+// store.ts
+// An extremely simple external store
+import { writable } from "svelte/store";
+export default writable(0);
+```