Record Phase 0 entry baseline: 820 passing, 2 pre-existing failures (Client.CLI.Tests.SubscribeCommandTests.Execute_PrintsSubscriptionMessage and Tests.MxAccess.MxAccessClientMonitorTests.Monitor_ProbeDataChange_PreventsStaleReconnect), 0 build errors, 167 build warnings. The two failures exist on v2 as of commit 1189dc8 and are unrelated to the rename. Phase 0 exit gate adapts the requirement to "failure count = baseline (2); pass count ≥ baseline (820)".
Branch-naming convention updated in implementation/overview.md and phase-0 doc: cannot use `v2/phase-N-slug` form because git treats `/` as path separator and `v2` already exists as a branch, blocking creation of any `v2/...` branch. Convention is now `phase-N-slug` (no v2/ prefix).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>