Fix Docker build and improve checks #220

This commit improves multiple aspects of Docker builds:

- Enable artifact output validation for Dockerfile.
- Correct the path references in Dockerfile for the distribution
  directory.
- Add Dockerfile specific indentation rules to `.editorconfig`.
- Use `npm run install-deps` for dependency installation, enhancing
  build reliability.
- Add automation script `verify-web-server-status.js` to verify running
  web server on given URL.
- Introduce automated build verification for Dockerfile:
  - On macOS, install Docker with colima as the container runtime
    because default agents do not include Docker and Docker runtime is
    not installed due to licensing issues (see actions/runner-images#17).
  - On Windows, there's no Linux container support (actions/runner#904,
    actions/runner-images#1143), so keep the checks for macOS and Ubuntu
    only.

Dockerfile

@@ -1,13 +1,16 @@
 # Build
-FROM node:lts-alpine as build-stage
+FROM node:lts-alpine AS build-stage
 WORKDIR /app
-COPY package*.json ./
-RUN npm install
 COPY . .
-RUN npm run build
+RUN npm run install-deps
+RUN npm run build \
+    && npm run check:verify-build-artifacts -- --web
+RUN mkdir /dist \
+    && dist_directory=$(node 'scripts/print-dist-dir.js' --web) \
+    && cp -a "${dist_directory}/." '/dist'
 
 # Production stage
-FROM nginx:stable-alpine as production-stage
-COPY --from=build-stage /app/dist /usr/share/nginx/html
+FROM nginx:stable-alpine AS production-stage
+COPY --from=build-stage /dist /usr/share/nginx/html
 EXPOSE 80
-CMD ["nginx", "-g", "daemon off;"]
+CMD ["nginx", "-g", "daemon off;"]