Development record

The v0.15.1 release review found at README.md:69; commands/announce.md: INCOMPLETE. The README says '`abcd status` needs git 2.29 or later, which reads a fetch's branches from its standard input (`git fetch --stdin`)'. `abcd announce` fetches the status branches by name through the same path: internal/core/claim/announce.go:95-96 sets ns.only and calls fetchWith, and remote.go:765-766 switches to `fetch --stdin` whenever a namespace has ns.only. So announce needs git 2.29 too once origin holds any status branch, and on an older git it refuses with an error that names 'the status fetch'. commands/announce.md does not mention…