[fentouxungui]

What is ShinyApps?

ShinyApps is a free, community-run desktop app store for Shiny applications
(store: https://github.com/fentouxungui/ShinyApps, catalog: https://fentouxungui.github.io/ShinyApps/catalog.json).
It packages a Shiny app together with a pinned R runtime into a self-contained desktop
bundle (Windows x64 and macOS arm64), so people who do not use R can install and run
spatialLIBD with one click -- no R installation, no devtools, no version conflicts.

Why this PR?

spatialLIBD is listed in that store, and the store needs a reproducible prebuilt artifact
to distribute. This PR adds one CI-only workflow file
(.github/workflows/build-app-bundle.yml). It does not touch application code,
DESCRIPTION, tests, or data.

On each tag the workflow:

1. installs the package and its CRAN/Bioconductor dependencies into a private library;
2. builds a self-contained bundle for Windows x64 and macOS arm64 (R 4.6.1);
3. runs a smoke test that actually starts the app;
4. attaches the two zip files to a GitHub Release.

What does it change for you?

• No source changes -- the diff is one YAML file.
• No maintenance burden -- no new dependencies and no app-logic review; the workflow
  is self-contained and can be deleted at any time.
• GitHub Actions minutes -- it runs only when a tag is pushed, not on every commit.
  Public repositories receive free standard-runner minutes; a full run is roughly
  10-20 minutes per platform.
• Credit and discoverability -- the store entry links back to this repository and
  its README, and users see your project as the source.

What do you need to do?

1. Review the single workflow file (no application code is changed).
2. Merge this PR -- or tell me if you would prefer a different filename or branch.
3. Optionally push a tag such as � to trigger the first build; I am
   happy to do that for you if you prefer.

If you would rather not have this in your repository, simply close the PR and I will
remove the store entry. No hard feelings.

Thanks for building spatialLIBD -- it is a great fit for the store, and this makes it
usable by people who do not have R.