The frame carried `agentPreset` for surfaces that label the session, but
nothing consumed it: `noteAgentPreset` ran only in the switching tab's RPC
callback, so a second connected client refetched its catalogs while its
session row — the header label's source, and the hero chip's no-op input —
kept the composition the session had replaced.
`SessionManager.handleHostEnvelope` now folds the frame like the other
session frames. Re-applying the switching tab's own frame is a no-op: the
merge lowers `blank` only and keeps the row's `updatedAt`.
Presets own the rows that decide what a session's `/` menu contains, but
both browser catalogs cache per session and had no invalidation edge for a
recompose: `commands/changed` is registry-wide and recomposing registers
nothing, so the menu kept serving the composition the session no longer ran.
The host stream now frames the logged `agent-preset/selected` commit as
`host/session-preset-changed`; the runtime bridges it to the typed
`session/preset-changed` event, `ui-command` soft-refreshes that session's
directory key and `ui-skill` invalidates its catalog entry.
Reaching the host on a second switch was a separate defect: the list-row
identity guard compared every summary field except `agentPreset`, and the
merge keeps the row's `updatedAt`, so a switched row looked unchanged and
served its cached instance forever. The hero chip compares the pick against
that row, so switching back to the creation-time preset sent no RPC at all.
The mid golden was racing the reasoning block's stream: captureStableAria
could freeze on the pre-render gap between steering acceptance and the
assistant step, pinning a snapshot without the Think row. Wait for the
[data-variant=think] row so the golden captures the complete assistant step.
Steering bubbles render as plain user bubbles; a mid-turn steer is
recognizable by its position in the flow. The runtime SteeringMessageNode
projection and pending-steering lifecycle are unchanged.
Partially supersedes the 2026-08-04 context-source and steer marks note;
the new simplification note owns the removal rationale.
The persistence catalog recognizes SessionEventMap augmentations of
'@deepseek-ai/dsh-session/types' alone, so the selected event's old
root-specifier declaration compiled but silently vanished from the
generated catalog. The hermetic scaffold e2e still addressed the skill
registry as a preset-realm service; under the layered host registry the
composed agent's view is a scope read, and the ambient-root isolation it
proves is unchanged.
The suite composes over the ambient DSH home, so a fixed session id
collides with the log a previous run persisted once the tool-execution
path checks persisted identity.
The shipped-Web e2e enables the bundled badge skill as a stand-in for a
repository plugin's deployment-level provider and asserts the layering both
ways: a standard-preset agent's view merges the global layer with its
preset's local discovery and its loader tool resolves the global skill,
while the host view stays global-only and a core-web agent can read the
layer but composes no loader tool.
This reverts commit f12c131ee9fdbc01b9294c8dc2c73cd36ab717cf.
The layered host skill registry closes the gap the bypass recorded: a
repository plugin's skill root registers into the global layer and reaches
every preset-composed session's catalog, so the fixture declares its skill
root again and the e2e proves the full skill, MCP, and TypeScript
contribution set. The accidental .claude/launch.json from that commit goes
with it.
The skills capability moves back to the host plane as one singleton, layered
with the ScopedLayers infrastructure the tools registry established: a
registration files into its calling context's layer (repository plugins and
host rows land global, a preset's skill-local lands in that preset's layer),
and a read merges the global layer with the viewing scope's chain, the
nearest layer winning duplicate names outright while rank keeps deciding
duplicates within one layer.
The web-app bundle re-enables the base skill registry row (skill-local and
tool-skill stay preset-owned), the standard preset drops its isolate skills
realm for bare rows over the host registry, tool-skill passes the calling
agent as the view scope, and the gateway's skills domain reads the host
registry in the presenter scope — a cold session now resolves its recorded
preset's standing key instead of failing.