build(theseus): ship webapps.js

The packaged app lists its files explicitly; the new module was not on
the list, so a packaged build failed at startup on a missing module.

package.json

@@ -82,6 +82,7 @@
       "messages-preload.js",
       "bcnr-preload.js",
       "bcnr-origin.js",
+      "webapps.js",
       "lib/**/*",
       "package.json",
       "node_modules/**/*",