Move testify mocks out of production files into hotline/hltest

The manager mocks lived in production source so that internal/mobius
tests could import them (test files are not importable across
packages), which pulled testify into the production dependency graph
of hotline importers, counted the mocks against coverage, and put them
in the library's godoc. They now live in hotline/hltest, an
httptest-style test-support package.

The hotline package's own in-package tests cannot import hltest (import
cycle), so the mocks they use are duplicated in mocks_test.go;
conformance assertions in both files catch signature drift.
MockAccountManager was only ever used inside internal/mobius and moves
to a _test.go file there.

0 files changed, 0 insertions, 0 deletions