The #592 fix added a devtools-detection probe, and the #592 follow-up
added a require_password probe + a branding-defaults whereIn().select().
Both shift the db() call indices the existing #550 test relied on, and
the branding probe needed `.select()` to resolve to an array (the mock
chain wasn't thenable, so `for..of` on the result threw → 500 on every
test that hit BASE_BODY).
Add `whereIn` + `selectResult` to buildChain so the branding probe
yields an iterable. Factor the three pre-slug app_settings chains into
a baseSettingsChains() helper and update each test's queued sequence
and toHaveBeenNthCalledWith / toHaveBeenCalledTimes expectations to
match the new shape. No behaviour change in v1/events.js — only the
test scaffolding moves.