Offline support

[cuibonobo]

While the client is connected, it should save images and metadata the local browser. The app should populate itself from this store if the connection is not available or is very slow.

[cuibonobo]

The localStorage API only allows strings and has strict data limits. A library that interfaces with IndexedDB would be more feasible here.

[cuibonobo]

The initialization behavior should be gathering metadata and images and putting them in a local store. When updates are received, they should also update the local store. Visiting the page without a network connection will retrieve the locally-stored values and display those while periodically re-checking the connection.