docs: replace vague provenance prose with recorded facts

.agents/notes/implemented/feature/2026-08-04-web-context-source-and-steer-marks.md

@@ -8,13 +8,13 @@ English | [中文](2026-08-04-web-context-source-and-steer-marks.zh.md)
 
 Everything a producer adds to the model-facing conversation reached the Web transcript as one of two anonymous shapes. Every logged non-user `user/message` — the skill catalog, the runtime snapshot, reconciled `AGENTS.md` instructions, a guard notice, a subagent report, a cross-session snapshot — collapsed into one identical `上下文注入` row, so a reader could not tell what had been added without expanding each row and reading raw JSON. Mid-turn steering was worse: it rendered in exactly the bubble a turn-opening prompt uses, leaving the transcript unable to say which message interrupted a running turn.
 
-The distinctions are already durable. `user/message.source` is the merge-extensible provenance every producer must supply, while `agent/inbox/spliced` records whether an identified message entered and left `next-turn` or `next-step`; only the presentation discarded them. The terminal transcript this Web UI replaced did name each card's producer, so the Web surface was a regression for the same log.
+The distinctions are already durable. Every producer must supply a merge-extensible `user/message.source` that identifies itself, while `agent/inbox/spliced` records whether an identified message entered and left `next-turn` or `next-step`; only the presentation discarded them. The terminal transcript this Web UI replaced did name each card's producer, so the Web surface was a regression for the same log.
 
 ## Decision
 
 The transcript names all three roles a non-prompt message can play — injected context, recalled session, and steering.
 
-`TranscriptAdapter` and the history fold attach a `provenance` view to every `ContextMessageNode`, computed by `contextProvenance()` from the durable source alone. It returns a `role` (`inject`, or `recall` for a cross-session snapshot) and a `label` naming the producer. `ContextInjectionRow` titles itself from the role and shows the label beside that title in `ToolRow`'s summary geometry, so the collapsed row already answers what was added and by whom; the 141px scrollport and truncation bound are unchanged from the [archived disclosure decision](../../archived/feature/2026-07-30-web-context-injection-disclosure.md). What renders inside that scrollport is chosen by the independent form axis added in the [context form decision](2026-08-05-context-form-vocabulary.md).
+`TranscriptAdapter` and the history fold attach a `provenance` view containing the producer role and label to every `ContextMessageNode`; `contextProvenance()` computes it from the durable source alone. It returns a `role` (`inject`, or `recall` for a cross-session snapshot) and a `label` naming the producer. `ContextInjectionRow` titles itself from the role and shows the label beside that title in `ToolRow`'s summary geometry, so the collapsed row already answers what was added and by whom; the 141px scrollport and truncation bound are unchanged from the [archived disclosure decision](../../archived/feature/2026-07-30-web-context-injection-disclosure.md). What renders inside that scrollport is chosen by the independent form axis added in the [context form decision](2026-08-05-context-form-vocabulary.md).
 
 **The label is read out of the log, never from a client-side table of producer names.** `workspace-instructions` is named by the distinct instruction paths it reconciled, `session-reference` by the titles of the sessions it read, a plugin source by its logged plugin id, and any other source by its own `kind` — the documented default arm for a merge-extensible union. A source carrying no readable kind degrades to an unnamed injection. A new or renamed producer is therefore identifiable without a client release, no label can go stale against the code, and a resumed, forked, or foreign log projects exactly like a live session.
 
@@ -24,7 +24,7 @@ The transcript names all three roles a non-prompt message can play — injected
 
 ## Alternatives considered
 
-**Localize producer names in the client.** A dictionary keyed by plugin id would read better than `@deepseek-ai/dsh-system-prompt`, but it drifts silently on every rename, needs a client change per new producer, and cannot name a producer from a foreign log at all. Provenance the log already carries is worth more than prose the client invents.
+**Localize producer names in the client.** A dictionary keyed by plugin id would read better than `@deepseek-ai/dsh-system-prompt`, but it drifts silently on every rename, needs a client change per new producer, and cannot name a producer from a foreign log at all. The producer name already recorded in the log is more reliable than a label the client invents.
 
 **Register presentations per source kind.** The disclosure decision deferred a keyed context-view slot until source-owned presentations emerged. Naming a row is not a distinct presentation, and a registry keyed on mounted producers would fail exactly where it matters — a resumed log whose producer is no longer mounted still has to render.
 
@@ -36,14 +36,14 @@ The transcript names all three roles a non-prompt message can play — injected
 
 ## Testing
 
-- `packages/client/runtime` unit coverage pins each provenance arm, the label fallbacks when a name field is missing, empty, or wrongly typed, the unnamed degradation for a source with no readable kind, and steering reconstruction on reset and live append paths.
+- `packages/client/runtime` unit coverage pins each source kind, the label fallbacks when a name field is missing, empty, or wrongly typed, the unnamed degradation for a source with no readable kind, and steering reconstruction on reset and live append paths.
 - `packages/client/ui-conversation` jsdom coverage pins the role title, the producer label beside it, the label's survival while expanded, the roleless header, and the steering caption on both durable and pending bubbles.
 - The keyless assembled-Web goldens carry the named header and the steering caption, so the assembled transcript — not only component tests — proves the marks.
 
 ## Consequences
 
 - A reader can attribute every non-prompt message in the transcript at a glance, and the header stays honest for logs this client version has never seen a producer for.
-- Producer names in the UI are package-shaped (`dsh-tool-skill`, `@deepseek-ai/dsh-system-prompt`) wherever the source carries only a plugin id. That is the cost of refusing a client-side name table; a producer that wants a better name records better provenance.
+- Producer names in the UI are package-shaped (`dsh-tool-skill`, `@deepseek-ai/dsh-system-prompt`) wherever the source carries only a plugin id. That is the cost of refusing a client-side name table; a producer that wants a better label must record one in its source fields.
 - `ContextMessageNode` gains a required field, so every constructed node — including test fixtures — must supply it.
 - `SteeringMessageNode` remains a distinct presentation node even though the agent loop now records admitted steering as `user/message`; its identity comes from the durable inbox history rather than a separate message event.
 - The `recall` arm has no producer in a shipped Web leaf until a host mounts `dsh-session-reference`; it is reachable only through logs written elsewhere.