fix(docker): build context = pwap root so shared/ is reachable

Vite aliases @pezkuwi/utils → ../shared/utils, so the Docker build context
must include both web/ and shared/. Previous context: ./web missed shared/
which caused 'Could not load /shared/utils/formatting' at module resolution.

Changes:
- Dockerfile WORKDIR=/build/web; COPY web/* and shared/* explicitly
- Workflow context: ./ + file: ./web/Dockerfile
- Move .dockerignore from web/ to pwap root (matches new context)

.github/workflows/quality-gate.yml

@@ -127,7 +127,7 @@ jobs:
       - name: Build and push
         uses: docker/build-push-action@v6
         with:
-          context: ./web
+          context: ./
           file: ./web/Dockerfile
           push: true
           tags: |