The shared coordinator serializes operations within one backend instance; it does not coordinate multiple instances writing the same on-disk session. Remove prose that implied unsupported shared-writer semantics.
Also update the older seam-simplification note to describe the surviving loadStored existence probe instead of the removed loadLive hook, so implemented documentation matches the current contract.
A configured root that already exists as a file or unreadable directory cannot host cwd buckets, but the backend previously mounted and deferred that deterministic configuration error until a later list or write.
Probe the resolved root while the plugin loads, surface every error except ENOENT, and keep an absent root valid for lazy first materialization. Document the timing contract, regenerate the config catalog, and pin the non-directory case at the load boundary.
JSONL discovered a log by the requested session id but later routed repair and append from the parsed header. A log selected for session A could therefore declare session B and redirect mutation to B.
Validate the requested id and exact header-derived cwd-bucket path before returning a stored prefix, reject duplicate ids across buckets, and repeat the id/cwd guards in the coordinator before repair or state publication. Collapse the redundant loadLive hook into loadStored while retaining the existing bucket layout and one-live-writer topology, avoiding flat-layout churn and a locator generic that SQLite and test backends do not need.
context/message previously defaulted to a <context source="…">…</context>
wrapper. No model is trained on a <context> tag either, and message
framing does not belong on the session surface: the surface projects the
durable log, and a caller that wants a frame formats its own content —
which the one heavy producer (workspace-context) already does with its own
<system-reminder> frame, opting out via 'raw'. The tag only added
machinery — ContextEnvelope plus an envelope field threaded through
InjectOptions, HookContext, the context/message event, and the agent-loop
inject/additionalContexts plumbing.
context/message now projects its content verbatim as a user-role message,
sharing one deriveEventMessage case with user/message and steering/message.
ContextEnvelope and every envelope field are removed; context/message.meta
still carries durable, model-hidden JSON state. Regenerated catalogs and
website API; refreshed the three affected keyless snapshots (envelope field
only; timestamps unchanged).
Broadens and renames the steering Agent Note to cover both envelope
removals as one decision.
Agent Note: .agents/notes/implemented/simplification/2026-07-20-unwrap-injected-content-envelopes.md
steering/message previously rendered inside a <steering source="…">
envelope like context/message. No model is trained on a <steering> tag,
so the framing is arbitrary markup the model was never taught to read;
recorded transcripts show it treating the instruction as third-party
metadata and refusing it. Framing also does not belong on the session
surface — a caller that wants a frame formats its own content. It now
projects verbatim as a plain user-role message; the <context> envelope is
untouched and renderTagged becomes context-only.
Agent Note: .agents/notes/implemented/simplification/2026-07-20-unwrap-steering-message-projection.md
