v0.1.30-pre.77

preview: nothing a person can see changes in this one. cordn-sync's jvm tests open their
databases on files, 60 sites in 49 files, conformance's two with them, and the build check that
refuses a new in-memory one now covers cordn-sync as well as ui and app-core. That closes the
class across the repository: nothing reachable by the lost-notification mechanism is left in
memory anywhere.

No migration: schema stays at 22 as at pre.76, so an account this build opens still needs
pre.61 or newer. Going back below that drops you at the account picker as though the account
were gone.

Landed from pr-pail, pull request dcdf582b at tip 4b5da039, merge f0fd9cc3. Fixes #47fcbf7a.