ci: add hosted app checks to workflow

Author: jarrodwatts

.github/workflows/ci.yml

@@ -15,3 +15,17 @@ jobs:
       - run: pnpm lint
       - run: pnpm test
       - run: pnpm build
+  app:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: pnpm/action-setup@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "22"
+          cache: pnpm
+      - run: pnpm --dir app install --frozen-lockfile
+      - run: pnpm --dir app check-types
+      - run: pnpm --dir app lint
+      - run: pnpm --dir app test
+      - run: pnpm --dir app build