preview static assets

[Fil]

The preview server should return the expected resource when the user requests a static asset ("files" — not pages and modules — declared in dynamicPaths).

This would allow e.g. to test embedded modules locally.

(Even though static assets are mostly intended for external consumption (for embedding), and not for use internally within a Framework application.)

(excerpted from #1681)

[mbostock]

@Fil Can you give this issue a proper description? I’m trying to remember what this issue is about. Does this only cover exported assets that are explicitly enumerated in dynamicPaths? Otherwise it seems likely that something that would work in Preview but then fail in production because you forgot to list it in dynamicPaths.

[Fil]

updated the description 👍