Third module of the tool/ coverage task, and the last small one.
Patched at the module's own boundary (firebase_client_for, FirebaseConfig.load
and sync_log), so nothing touches Firebase. The assertions are deliberately
about the *shape* handed to sync_log rather than about sync_log working --
test_sync.py already covers the latter. This tool exists so
crdt_sync_dart/tool/interop_check.dart has a Python-written record to find, so
the things worth pinning are the ones that would make the two halves silently
miss each other: the _interop/devices prefix, the pydev device id, the py-rec
id with its exact value and Hlc, the library's own codec rather than a local
reimplementation, and the in-memory revision store that keeps the seed
repeatable after the Dart side deletes both devices' data.
crdt_sync 286 -> 293 passed, still 100%. 3 of 7 tool/ modules done; the
config flip stays last.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CFSGeWxHPY5rHUGrPqhcmG
