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.

5 files changed, 14 insertions, 17 deletions

diff --git a/.github/dependabot.yml b/.github/dependabot.yml
index b2cce07..6351ffb 100644
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -12,7 +12,7 @@ multi-ecosystem-groups:
 
 updates:
   - package-ecosystem: "npm"
-    directory: "/ui"
+    directory: "/packages/ui"
     multi-ecosystem-group: "infrastructure"
 
   - package-ecosystem: "cargo"
diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index 8ee79a4..3cbad39 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -3,11 +3,11 @@ name: UI Checker
 on:
   push:
     paths:
-      - "ui/**"
+      - "packages/**"
       - ".github/workflows/check.yml"
   pull_request:
     paths:
-      - "ui/**"
+      - "packages/**"
       - ".github/workflows/check.yml"
   workflow_dispatch:
 
@@ -28,16 +28,15 @@ jobs:
         with:
           node-version: 22
           cache: "pnpm"
-          cache-dependency-path: "ui/pnpm-lock.yaml"
+          cache-dependency-path: "pnpm-lock.yaml"
 
       - run: pnpm install
-        working-directory: ui
 
       - run: pnpm check
-        working-directory: ui
+        working-directory: packages/ui
 
       - run: pnpm lint
-        working-directory: ui
+        working-directory: packages/ui
 
       - run: pnpm format
-        working-directory: ui
+        working-directory: packages/ui
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index b1e7254..d5bd131 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -4,7 +4,7 @@ on:
   push:
     branches: ["main", "dev"]
     paths:
-      - "ui/**"
+      - "packages/**"
   workflow_dispatch:
 
 permissions:
@@ -27,16 +27,15 @@ jobs:
         with:
           node-version: 22
           cache: "pnpm"
-          cache-dependency-path: "ui/pnpm-lock.yaml"
+          cache-dependency-path: "pnpm-lock.yaml"
 
       - run: pnpm install
-        working-directory: ui
 
       - run: pnpm format
-        working-directory: ui
+        working-directory: packages/ui
 
       - run: pnpm lint:fix
-        working-directory: ui
+        working-directory: packages/ui
 
       - name: Commit changes
         uses: stefanzweifel/git-auto-commit-action@v5
diff --git a/.github/workflows/semifold-ci.yaml b/.github/workflows/semifold-ci.yaml
index d42b4e1..7938a9d 100644
--- a/.github/workflows/semifold-ci.yaml
+++ b/.github/workflows/semifold-ci.yaml
@@ -73,7 +73,7 @@ jobs:
         with:
           node-version: 22
           cache: "pnpm"
-          cache-dependency-path: "ui/pnpm-lock.yaml"
+          cache-dependency-path: "pnpm-lock.yaml"
 
       - name: Install Node.js Dependencies
         run: pnpm install
@@ -182,7 +182,7 @@ jobs:
         with:
           node-version: 22
           cache: "pnpm"
-          cache-dependency-path: "ui/pnpm-lock.yaml"
+          cache-dependency-path: "pnpm-lock.yaml"
       - name: Install Node.js Dependencies
         run: pnpm install
       - name: Download build artifacts
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 402de0e..b58d10e 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -5,7 +5,7 @@ on:
     branches: ["main"]
     paths-ignore:
       - "**.md"
-      - "ui/**"
+      - "packages/**"
   pull_request:
     branches: ["main"]
   workflow_dispatch:
@@ -78,7 +78,6 @@ jobs:
 
       - name: Install Frontend Dependencies
         if: github.event_name == 'workflow_dispatch'
-        working-directory: ./ui
         run: pnpm install
 
       - name: Install Tauri CLI