A stronger durability test (dispose MID-turn, then re-load from disk) caught
that the original two-sibling-effect design dropped the loop's closing
`turn/end` on the bare fiber-dispose path: a fiber unload disposes sibling
effects CONCURRENTLY (`Promise.all`, vendor/cordis/fiber.ts), so the
session-create effect detached `onAppend` racing the loop's final
`session/flush` — the re-loaded log showed crash-recovery's synthetic
`interrupted` closer instead of the real `disposed` reason. The disconnect
path happened to work (only `quiesce()` ran), but the contract must hold
uniformly.
Fix: fold the session lifecycle INTO the agent's single composite effect.
`SessionStore` now exposes `prepare` (validate + construct, no store entry),
`enter` (attach onAppend + store, returns detach), and `announce` (emit
session/created), replacing the sibling-effect `createOwned`. `AgentLoop.start`
builds ONE effect that yields, in order: session-detach, register, then
stop-and-`await agent.done`. LIFO disposal runs them as an ORDERED chain (the
runtime awaits each disposer's promise before the next), so the loop is
stopped and awaited to exit — its closing flush captured through the still-
attached onAppend — BEFORE the session detaches, whether the trigger is the
handle's dispose() OR a fiber unload. The config path uses prepare()+start
too, so it gets the same ordered teardown. All three factory entrypoints now
funnel through the one composite builder.
The mid-turn durability test asserts the REAL `disposed` reason lands on disk
(not a recovered `interrupted` substitute), proving the closing event was
captured rather than reconstructed.
Tianyi Cui
a53a56ff48