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 title now comes from an attached session's live projection cut or a cold
one's durable checkpoint, and from nothing else. Attachment is decided by the
session store at read time, so a session that attached after the listing is no
longer answered from a checkpoint its log has moved past — the stale-title case
`api-session.list` already handles this way.
The log fold and its per-log memo are gone. Folding one title costs a whole
log, and this call sits under every keystroke; a session no projection answers
for is labeled by its id and regains its title the first time it is opened.
`lib` leaves the default exclusions: Ruby gems and many npm packages keep
sources there, and the miss would be silent and total. A traversal whose root
is unreadable now rejects instead of publishing an empty index over entries
that are still good, which is what the stale-while-revalidate path claimed but
could not do while every readdir error was swallowed. A drill marks the menu
drilled only when its edit actually reached the draft.
Refs #3154
Refs #3180
The Host session list already carries each session's `updatedAt`, which is
the number its own rows show; reading it there keeps the two surfaces from
disagreeing and avoids making a context capability depend on the BFF
assembly that owns the `sessionListMetadata` projection. A session the list
does not carry falls back to the candidate's creation time.
Refs #3154
Session candidates labelled from projection checkpoints instead of a full
log fold per keystroke, with the uncheckpointed remainder folded once and
memoized while its log stays cold. The file index keeps answering while an
invalidated traversal rebuilds behind the caret, and its default exclusions
now cover build outputs so deep sources stay reachable.
Rows carry only what distinguishes them: a file names its parent directory,
a session names its workspace only when that workspace is not the current
one, and a drilled listing names none because its new breadcrumb does.
Resolves#3180
Related to #3154
