Read-support refs-v1; explain fetches a git-refs checkpoint on clone
Commit
Soph2mo ago
- checkpointpolicy: refs-v1 is now read- AND write-supported (refsV1Format added to both readFormats and writeFormats) so explain/resume/attach accept git-refs checkpoints and the git-refs store may write them. Tests that used "refs-v1" as a stand-in unsupported version now use "refs-v2" (the next, genuinely unsupported refs major); format_test asserts refs-v1 is supported.
- explain: on a fresh clone the prefix→ID remote fallback only fetched the v1 metadata branch (empty under git-refs). When the primary is git-refs and the prefix is a full checkpoint ID (the Entire-Checkpoint trailer always is), fetch that one ref via FetchCheckpointRef and re-list.
Co-Authored-By: Claude Opus 4.8 (1M context) noreply@anthropic.com Entire-Checkpoint: 291fe479c0a8