Tool and prompt-section visibility is inherited along dsh-scope's parent
chain, and an agent's scope key is minted with no parent. Per-session agent
presets moved every model-facing row onto the agent plane and made
AgentPresets.mount() the one thing that binds that link, from the api-proxy's
session create, resume, and fork paths. The two in-process subagent drivers
installed only the per-child persona and tool filter, so a child's scope chain
had length one and its registry view resolved the global layer alone — which
is empty wherever a preset roster is composed. One-shot children reached the
model with no tools, continuable ones with only the host-plane `report`, and
neither carried its parent's persona, workspace context, or skill catalog.
AgentPresets.composeFrom() joins one agent to the standing composition another
already runs on. It is a bind, not a mount: the child gets its parent's exact
generation, so a composition edited since the parent started cannot fork it
onto another one, and it is synchronous, which is what lets a child creation
window use it. applyChildComposition() now takes the parent and performs the
join first, making a child composed without it unrepresentable at the call
sites. childSessionMeta() records the joined id so a cold read rebuilds the
composition the child actually ran under.
The audit that followed found two api-proxy readers on the wrong authority:
presenterScopeFor() and the live-agent branch of assertPresetUnchanged() both
read header.agentPreset, which goes stale the moment a blank session switches
preset. A switched session's cold transcript resolved presenters in the older
composition's layer and silently degraded to generic cards, and the gateway
refused to adopt a live session under the preset it actually runs while
accepting the one it left. Both now resolve through resolveSessionPreset(),
matching the resume branch fifteen lines above. The owning architecture Agent
Note carried the stale claim that the header records what a session runs; it
is corrected to name the header/log pair and its three readers.
Fixes#2165
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.
setScopeParent could re-link any key from anywhere, leaving the
blank-session-only recompose rule entirely to caller discipline. The
relation now binds once — a second bind throws — and re-linking exists
only on the ScopeParentBinding returned to the original binder, the
private-capability shape the package conventions prescribe for a
single-caller operation. The preset roster keeps each composed agent's
binding in a WeakMap keyed by the agent, making it the sole authority
that can move an agent between standing compositions; the blank-session
contract itself stays with the gateway, which alone can see what a
session logged.
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 durable sandbox/acl-session event carried a workspace binding that
always equals the session cwd and a random temp path that only needed
to be stable per session. Both are now derived: the temp subdirectory
is sha256(session id + workspace), created exclusively and removed on
provider dispose, so fork/resume semantics fall out of the derivation
and the record, its fold/provision/tamper validation, the immediate
flush kick, and the session-store dependency all disappear.
The persistence catalog recognizes augmentations of
'@deepseek-ai/dsh-session/types' alone, so the old root-specifier
declaration compiled but silently vanished from the generated catalog; the
Agent Note also drops its internal repository link for the public-links
gate, and the persistence catalog pair re-records with the restored
agent-preset section.
