[takashi-matsuyama]

Summary

basou import claude-code groups the transcripts of a conversation by their first record and lets the one whose file was created first keep the shared records, importing each later one without them (#377). Birth times are read from the files on every import, and they can change after one (a restore from a backup, a copy to another disk). When they flipped:

• the session holding the shared records was re-derived without them, while the fork, whose session begins after its copies, did not take them back, so they were counted in no session;
• between two forks, when the earlier one grew after a later one had copied from it, the earlier one dropped the records the later one copied, and nothing reported it.

This change:

• Transcripts already imported keep the order in which their sessions begin, within the places they hold by birth time (a stable sort: two sessions that begin together keep their birth order).
• A transcript not imported yet keeps its place by birth time, unless it holds a copy of a record an imported fork's session counts; then it forked from that fork and goes after it. The files are read for this only when such a transcript sits before an imported fork.
• The session store is loaded, with the existing symlink checks, before the conversations are indexed, and passed to the shared import core, so it is still read once per run.
• docs/spec/terminal-and-import.md section 14.2 and the Unreleased changelog entry describe the rule and the three cases the order still cannot recover from the files.

No on-disk format change.

Tests

New cases in packages/cli/src/commands/import.test.ts (forked transcripts):

• birth times flip after an import: nothing is re-derived, and both sessions' events are unchanged;
• the original grows after the flip and keeps the shared records;
• a fork of a fork flips with its parent, and the parent grows: it keeps what the later fork copied;
• --force after the flip re-creates the sessions in the order they began;
• a fork and an original both imported with the shared records (as an earlier basou left them) are still re-derived by birth order;
• a new fork of an imported original, and a new fork of a fork, are placed by birth time;
• a transcript not imported yet whose restored birth time falls before an imported fork it copied from goes after that fork (in two orders);
• an original not imported yet stays before an imported fork it holds nothing of.

Checks run: pnpm -r build, pnpm typecheck, pnpm lint, pnpm lint:lang, pnpm lint:paths, pnpm test, pnpm test:scripts.