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, 41 insertions, 0 deletions

diff --git a/packages/ui/package.json b/packages/ui/package.json
new file mode 100644
index 0000000..943fddc
--- /dev/null
+++ b/packages/ui/package.json
@@ -0,0 +1,41 @@
+{
+  "name": "@dropout/ui",
+  "version": "0.2.0-alpha.1",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "preview": "vite preview",
+    "check": "svelte-check --tsconfig ./tsconfig.app.json && tsc -p tsconfig.node.json",
+    "lint": "oxlint .",
+    "lint:fix": "oxlint . --fix",
+    "format": "oxfmt . --write"
+  },
+  "dependencies": {
+    "@tauri-apps/api": "^2.9.1",
+    "@tauri-apps/plugin-dialog": "^2.6.0",
+    "@tauri-apps/plugin-fs": "^2.4.5",
+    "@tauri-apps/plugin-shell": "^2.3.4",
+    "lucide-svelte": "^0.562.0",
+    "marked": "^17.0.1",
+    "node-emoji": "^2.2.0",
+    "prismjs": "^1.30.0"
+  },
+  "devDependencies": {
+    "@sveltejs/vite-plugin-svelte": "^6.2.1",
+    "@tailwindcss/vite": "^4.1.18",
+    "@tsconfig/svelte": "^5.0.6",
+    "@types/node": "^24.10.1",
+    "@types/prismjs": "^1.26.5",
+    "autoprefixer": "^10.4.23",
+    "oxfmt": "^0.24.0",
+    "oxlint": "^1.39.0",
+    "postcss": "^8.5.6",
+    "svelte": "^5.46.4",
+    "svelte-check": "^4.3.4",
+    "tailwindcss": "^4.1.18",
+    "typescript": "~5.9.3",
+    "vite": "npm:rolldown-vite@7.2.5"
+  }
+}