threadsState gives one row per session with `session` and `legacy`; threadIdle
idles a run against its bound session. Each session gets its own store
(threads/<b>/<t>/sessions/<s>/, or the thread's old store for a legacy-3l
session) and its own workspace (session-workspaces/<b>/<i>/<s>/), held by an
O_EXCL <ws>.lock from before the clones to the run's proven exit. A legacy
session's workspace binds in-sandbox at the old instance path. sessions.json
is v2 and reads v1. New tests: cli session-launch.test.mjs, seat
session-workspace.test.mjs. Not yet run: tests wait for Sage's CLEAR.
Two old assertions change as exact updates:
- mos-1285: end-launch.test.mjs threadsState deepEqual. The old row shape was
{ thread: 'th-1', instance: 'coder', pending: 0, unread: 0, lastMessage: null,
lastOpen: '2026-10-15T00:00:01.000Z', lastClaim: null, holder: null }; the
row keeps every key and value and adds session: 'th-1', legacy: true.
- mos-1289: thread-launch.test.mjs:182, old line
`const store = join(f.dataRoot, "threads", "acme", A);`
now reads A's default session id from threadsState's `session` key; :183-185
unchanged; one added assert that threads/acme/<A>/session is absent.
jason.woltje
2133c5a0c6