feat(graph): add Federation Graph page and enhance coverage

Adds a new Federation Graph page to display subgraphs and their 
schemas. Implements loading state and error handling. Enhances 
coverage reporting by including 'lcov' format for better insights 
into test coverage metrics.

Dockerfile

@@ -7,7 +7,10 @@ RUN npm install --global node-gyp && \
 COPY ./package.json ./package-lock.json ./
 RUN npm ci --no-progress
 COPY . /build
-RUN npm run generate
+RUN npm run postinstall && npm run generate && npm run lint && npm run test:coverage
+
+FROM scratch as export
+COPY --from=builder /build/coverage /
 
 FROM amd64/nginx:1.29.3@sha256:4fd8a65a560a906addb9930f2cd5a3d33ff5b8e8b50e983bce275c9c78151a96
 MAINTAINER Joakim Olsson <joakim@unbound.se>