Replace the remaining private MockDatabaseInterface/FakeServer copies in the forced-password, room-channel, movecard, and random-reveal tests with InMemoryServer_DatabaseInterface and ServerTestFixture. The room-channel test keeps its log assertions against the shared logEntries; the forced-password test seeds its moderator user and auth result through the fixture knobs. Delete movecard_tests/server_test_helpers.h.
* [Servatrice] Log room channel messages and bump schema to 38
* Fixup: show room_channel audit rows and keep migration nullable
The log history query returns room_channel rows, but the log tab
dropped them. Render them in the room table with an extra Channel
column. Also drop the NOT NULL on target_type from the 37->38
migration so migrated schemas match the nullable servatrice.sql
definition (and strict-mode ALTERs cannot fail on legacy NULL rows).
Update the channel tests to the flag-based privilege model: the admin
fixture now carries IsModerator alongside IsAdmin, as the database
layer assigns.
---------
Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>
