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
Apply global visual polish across the web client: corner-shape:
superellipse(1.5) with corner-shape: round pairing for full circles,
elevation tokens that draw 0.5px stroke outlines inside box-shadow for
floating surfaces, 0.5px hairline borders and divider lines for
neutral-token strokes, and tuned stroke contrast plus larger radii for
menus, settings panels, and cards. Stylesheet-scan specs in ui-theme
reject unpaired circles, border+shadow mixes, and 1px neutral hairlines
repo-wide.
Closes#3287
Turtle