The persistence seam is now create/open/stat/list returning per-session
SessionHandles (read/append/flush/close); every log read and write flows
through the owning handle. The seam package exports only the service and
handle contracts, consumer-visible errors, and pure durable-data
validation helpers; each backend owns its complete storage runtime, and
the shared contract suites pin equivalent observable behavior. The
backend routes published sessions' live events by id into the active
write handle; agent-loop only acquires, seeds, and closes the handle.
Resume appends interruptedTurnClosers through its write handle;
session-query owns the revision-keyed cold cache. Legacy-only surfaces
are removed in the same swap: locate/readRaw/supportsRawArtifacts, the
legacy event-shape read migration, zstd torn-frame salvage,
DSH_SESSION_JSONL, and hook transcript_path population; a torn final
zstd frame is discarded whole; the session-list cold blank probe returns
on stat metadata (eventCount derived from the last physical row,
sizeBytes). The WebUI ZIP export serializes the logical log from a read
handle, so both backends export identically.
Refs #3245
A jump clicked while the Load-earlier pull was in flight fell through the
settle effect's nearest-turn fallback and landed on the wrong row. The
effect now keeps the pending jump (busy pulse stays) while loadingOlder is
true and a retry tick re-issues loadThrough when the pull settles.
Also repins the long-interactions e2e rail block to the outline-rail
semantics (fixed mark pitch, load-and-jump labels) and covers the
loadThrough forwarding paths in apply-inject and the client-runtime stub.
Outline entries gain the turn's final text-bearing assistant preview:
each assistant message overwrites a state draft and turn/end commits
the survivor, matching the loaded rail's findLast semantic; the bare-
array wire keeps its identity across draft changes, so pushes stay at
three per turn. Preview budgets shrink to the rail card's clamps — one
50-character prompt line, up to three 120-character response lines,
ellipsis on clip — on loaded and unloaded turns alike (stateVersion 2
discards v1 cache rows).
A mid-paging landing keeps the jump armed with the target row as its
paging anchor, so later chunks and the load-earlier button's unmount
cannot drift the landing; the loader's completion runs one final
correction unless the reader already scrolled off the target. Adds the
browser contract: full outline ladder, keyboard jump on an unloaded
mark, landing geometry, and rail fades.
