App Engine config for static sites with 404

app.yaml

# This app.yaml file assumes your static site is built into a directory called dist.
# Make sure dist only contains files you want to be made public. At a minimum, dist
# should contain an index.html and a 404.html.

# This can be any standard environment https://cloud.google.com/appengine/docs/standard/
runtime: python312

handlers:
  # Handle files
  - url: /(.+)
    require_matching_file: true
    static_files: dist/\1
    upload: dist/(.+)

  # Handle directories
  - url: /(.+)/
    require_matching_file: true
    static_files: dist/\1/index.html
    upload: dist/(.*)/index.html

  # Handle root index
  - url: /
    require_matching_file: true
    static_files: dist/index.html
    upload: dist/index.html

  # Handle not found
  - url: /.*
    static_files: dist/404.html
    upload: dist/404.html