Change Details

## Overview When navigating an album (`/{username}/{album}`) that doesn't exist, we should show a "not found" message. If the `username` is valid, we should provide easy navigation back to the user. Otherwise we should provide the standard navigation (logged in or out).

## Overview When navigating an album (`/{username}/{album}`) that doesn't exist, we should show a "not found" message. If the `username` is valid, we should provide easy navigation back to the user. Otherwise we should provide the standard navigation (logged in or out). Right now, we return the error as a raw JSON string.

## Overview When navigating an album (`/{username}/{album}`) that doesn't exist, we should show a "not found" message. If the `username` is valid, we should provide easy navigation back to the user. Otherwise we should provide the standard navigation (logged in or out). Right now, we return the error as a raw JSON string.