356 -> sync_service_test (133) + sync_service_revision_test (96) +
sync_service_fakes (163).
The underscores came off every shared fake: Dart privacy is library-scoped,
so `_FakeRemote` declared in one file is invisible to the next. `_peerLog`
became `buildPeerLog` rather than `peerLog`, because two tests declare a
local variable of that name and the helper would have been shadowed by its
own caller.
The `_revisionTrackingTests()` indirection is gone -- that function existed
only to keep main() readable, which is now the file boundary's job.
Verified: 313 tests pass, 100% coverage. Only CLAUDE.md and
docs/desktop-performance-findings.md remain over 250 lines.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
