Manage frontend dependencies via npm / package.json

Currently, our frontend dependencies all reside in app/static/third-party, and we use the naming pattern ./library-name/version/file.js.

That way, we are depending on pre-built script-type versions of the libraries, and have to dump them into the global namespace via <script src=""> tags.

Since we are using JS modules for our own JS code, it could be nicer to use module-type versions of the libraries, and have them automatically installed via npm from the package.json file.

It’s possible (and not uncommon) to check in the node_modules folder into the repository, to rule out the failure case of the npm servers being down at install time, or other leftpad-like shenanigans.

npm supports specifying the install location via the --prefix option, so we can install to app/static/node_modules, for example.

Start by reviewing app/static/third-party, the existing frontend <script src> usage, and the current JavaScript module setup. Define how package.json should manage those dependencies and whether they belong under app/static/node_modules; done means the frontend no longer relies on the current checked-in global-script layout and the chosen installation approach is reproducible.