ci(docs): pre-build @rozie/runtime-engine-helpers before docs build

The docs workflow builds each runtime package explicitly (not via turbo)
because docs's @rozie/unplugin compilation pulls .rozie examples whose
emit imports from @rozie/runtime-{vue,engine-helpers,…}. With the new
@rozie/runtime-engine-helpers package landed in quick-260526-q7s (which
SortableList.rozie now imports via useSortableJS), the docs build
started failing at Rollup entry resolution because dist/ doesn't exist
on a fresh CI checkout.

Adds the build step alongside the existing runtime-vue one + adds the
package's source path to the workflow path filter so future changes
trigger redeploys.

The matrix workflows (vue/solid/lit/etc.) use `pnpm turbo run build`
which auto-picks the new package via the workspace graph, so they need
no change. Adoption Smokes already passed on the prior push.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: serpentblade

.github/workflows/docs.yml

@@ -16,6 +16,7 @@ on:
       - 'packages/targets/**'
       - 'packages/unplugin/**'
       - 'packages/runtime/vue/**'
+      - 'packages/runtime/engine-helpers/**'
       - 'examples/*.rozie'
       - '.github/workflows/docs.yml'
   workflow_dispatch:
@@ -63,6 +64,15 @@ jobs:
       - name: Build @rozie/runtime-vue
         run: pnpm --filter @rozie/runtime-vue run build
 
+      # @rozie/runtime-engine-helpers (added 2026-05-27, quick task 260526-q7s)
+      # is referenced by examples/SortableList.rozie via
+      # `import { useSortableJS } from '@rozie/runtime-engine-helpers'`.
+      # When the docs site's @rozie/unplugin compilation pulls any .rozie
+      # example that has SortableList in its dep graph, Vite resolves the
+      # import against this package's dist/.
+      - name: Build @rozie/runtime-engine-helpers
+        run: pnpm --filter @rozie/runtime-engine-helpers run build
+
       - name: Build docs
         run: pnpm --filter @rozie/docs build