Merge remote-tracking branch 'origin/master' into session-query-tool

# Conflicts:
#	docs/architecture.i18n.yaml

docs/core-data-structures/core.md

@@ -323,7 +323,7 @@ Source: [`packages/core/session/src/types.ts`](../../packages/core/session/src/t
  *
  * The {@link sourceEventSeqs} and {@link surfaceOp} fields are conditional:
  * they only exist on {@link SurfaceEventType} variants (`user/message`,
- * `assistant/message`, `tool/result`, `context/message`, `steering/message`).
+ * `assistant/message`, `tool/result`, `steering/message`).
  * Non-surface events (boundary markers, chunks, usage, errors) never carry
  * surface metadata — the compiler enforces this at `Session.append()`
  * call sites.
@@ -351,7 +351,7 @@ type SessionEvent<T extends SessionEventType = SessionEventType> = {
 }[T]
 ```
 
-The fourteen event variants (`turn/start`, `turn/end`, `step/start`, `step/end`, `user/message`, `prompt/blocked`, `context/message`, `assistant/chunk`, `assistant/message`, `tool/call`, `tool/result`, `steering/message`, `todo/write`, `request/header`), the `deriveMessages()` projection rules, the `TurnTrigger`/`TurnEndReason` reasons, and the turn-enclosure invariant are on **[session.md](session.md)**. How the log is made durable — the `SessionPersistence` seam, JSONL/SQLite backends, the `session/flush` checkpoint, crash recovery, and `SessionHeader` — is on **[persistence.md](persistence.md)**.
+The thirteen event variants (`turn/start`, `turn/end`, `step/start`, `step/end`, `user/message`, `prompt/blocked`, `assistant/chunk`, `assistant/message`, `tool/call`, `tool/result`, `steering/message`, `todo/write`, `request/header`), the `deriveMessages()` projection rules, the `TurnTrigger`/`TurnEndReason` reasons, and the turn-enclosure invariant are on **[session.md](session.md)**. How the log is made durable — the `SessionPersistence` seam, JSONL/SQLite backends, the `session/flush` checkpoint, crash recovery, and `SessionHeader` — is on **[persistence.md](persistence.md)**.
 
 ## The agent handle
 
@@ -361,8 +361,9 @@ Source: [`packages/core/agent/src/types.ts`](../../packages/core/agent/src/types
 
 ```ts type-equiv
 /**
- * Message options. An omitted source attests direct human input as `{ kind: 'user' }`
- * and may authorize policy consumers, so non-human producers must label their content.
+ * Options for {@link Agent.followup}, {@link Agent.queue}, and {@link Agent.steer}.
+ * An omitted source attests direct human input as `{ kind: 'user' }` and may
+ * authorize policy consumers, so non-human producers must label their content.
  */
 interface SendOptions {
   source?: MessageSource
@@ -372,19 +373,90 @@ interface SendOptions {
    * records them directly at its next checkpoint.
    */
   contexts?: HookContext[]
+  /** Opaque JSON state retained on the durable message but hidden from the model. */
+  meta?: JsonValue
 }
 ```
 
-`InjectOptions` accepts ordinary message attribution and durable model-hidden JSON metadata. Attached contexts belong only to queued or steering input, so synthetic injection cannot accept them:
-
 ```ts type-equiv
 /** Options specific to durable synthetic context injection. */
-interface InjectOptions extends Omit<SendOptions, 'contexts'> {
-  /** Opaque JSON state retained in the session event but hidden from the model. */
+interface InjectOptions {
+  /** Defaults to `{ kind: 'plugin', plugin: '' }`; non-human producers should identify themselves. */
+  source?: MessageSource
+  /** Opaque JSON state retained on the durable message but hidden from the model. */
   meta?: JsonValue
 }
 ```
 
+The advanced acceptance form makes every default explicit and rules out attached contexts on injection:
+
+```ts type-equiv
+/**
+ * Fully specified input for {@link Agent.send}. Unlike the intent-named
+ * helpers, this form applies no defaults: callers provide content, source,
+ * contexts, metadata (including explicit `undefined`), target, and wakeup.
+ * The union excludes attached contexts from non-waking next-step injection.
+ */
+type ResolvedAgentInput = {
+  content: ContentBlock[]
+  source: MessageSource
+  meta: JsonValue | undefined
+} & (
+  | { target: 'next-turn'; wakeup: boolean; contexts: HookContext[] }
+  | { target: 'next-step'; wakeup: true; contexts: HookContext[] }
+  | { target: 'next-step'; wakeup: false; contexts: [] }
+)
+```
+
+FIFO delivery methods return an opaque `AgentMessageId`, stable across that message's `agent/inbox/*` events. Injection returns an id but bypasses those events:
+
+```ts type-equiv
+/**
+ * Opaque id assigned to one accepted agent input. FIFO inputs carry the same id
+ * on their `agent/inbox/*` events; injection bypasses those events.
+ */
+type AgentMessageId = Branded<'AgentMessageId'>
+```
+
+The `agent/inbox/*` live events carry one accepted message; injection bypasses the FIFOs and never appears on them:
+
+```ts type-equiv
+/**
+ * One accepted FIFO message, carried by the `agent/inbox/*` live events. `id`
+ * is the value returned by the accepting helper or {@link Agent.send},
+ * stable across this message's enqueue, dequeue, and discard events. Source
+ * defaults, when applicable, are already applied, so these are the exact values
+ * the item was accepted with.
+ * `steering` is true for an item drained between steps; otherwise it is claimed
+ * at a turn boundary. `SendOptions.meta` is intentionally omitted: it is durable
+ * model-hidden state that lands on the eventual `user/message`/
+ * `steering/message`, not live-event routing data.
+ */
+interface AgentMessage {
+  /** The id returned by the accepting helper or {@link Agent.send}. */
+  id: AgentMessageId
+  content: ContentBlock[]
+  source: MessageSource
+  contexts: HookContext[]
+  /** Whether the item joined the steering FIFO rather than the queued FIFO. */
+  steering: boolean
+  /** Whether the item wakes the driver or requests another step. */
+  wakeup: boolean
+}
+```
+
+```ts type-equiv
+/** Options for {@link Agent.cancel}. */
+interface CancelOptions {
+  /**
+   * Preserve queued and steering inbox items instead of discarding them. The
+   * active turn is still aborted, but un-started and pending work survives for a
+   * later turn and no `agent/inbox/discard` fires.
+   */
+  keepInbox?: boolean
+}
+```
+
 ```ts type-equiv
 /** Stable runtime cause accepted by {@link Agent.cancel}. */
 type AgentCancelCause =
@@ -392,59 +464,97 @@ type AgentCancelCause =
   | { readonly kind: 'parent' }
 ```
 
+The structural `Agent` interface exposes four intent helpers plus the fully resolved acceptance method. The concrete driver implements the matrix once, and each helper supplies its fixed routing and defaults.
+
 ```ts type-equiv
 /** Public agent handle; its concrete implementation is internal to `@deepseek-ai/dsh-agent-loop`. */
 interface Agent {
   /** The single identity shared with {@link session}. */
   readonly id: SessionId
+  /** The provider route and model this agent's requests use. */
   readonly options: AgentOptions
+  /** The live session this agent drives; its log is the durable source of truth. */
   readonly session: Session
+  /** The current lifecycle state, mirrored on every `agent/status` transition. */
   readonly status: AgentStatus
   /** Agent-scoped context; its contributions are agent-local, unwind on disposal, and reject registration afterward. */
   readonly ctx: Context
 
   /**
-   * Queue one detached, frozen lossless-JSON item. If claimed, it is the sole
-   * ordinary message in its FIFO-ordered turn; the next claimed item waits for
-   * that turn's checkpoint.
-   * Attached contexts share the same snapshot and ownership boundary. Invalid
-   * input throws synchronously before notification or enqueue.
+   * Queue an ordinary message as its own FIFO-ordered turn and wake the driver.
+   * Content, resolved source, and attached contexts are detached, validated,
+   * and frozen together; invalid input throws synchronously before notification
+   * or enqueue.
+   * @param content - the prompt content blocks.
+   * @param options - source, attached contexts, and durable model-hidden meta.
+   * @returns the accepted message's {@link AgentMessageId}, stable across its `agent/inbox/*` events.
    */
-  send(content: ContentBlock[], options?: SendOptions): void
+  followup(content: ContentBlock[], options?: SendOptions): AgentMessageId
 
   /**
-   * Submit steering while the agent is `running`. An open turn records it at
-   * the next steering checkpoint before a request or continuation decision;
-   * policy may stop before another step. After turn close and its checkpoint,
-   * any remainder is queued for a later turn; terminal `agent/turn-stop`,
-   * cancellation, or disposal may discard it. Uses the same synchronous
-   * snapshot-and-validation boundary as {@link send}; when idle, delegates to it.
+   * Queue an ordinary message without waking an idle driver. The item retains
+   * FIFO order and is claimed only after another input wakes the driver. A lone
+   * queued item leaves `whenIdle()` resolved.
+   * @param content - the prompt content blocks.
+   * @param options - source, attached contexts, and durable model-hidden meta.
+   * @returns the accepted message's {@link AgentMessageId}, stable across its `agent/inbox/*` events.
    */
-  steer(content: ContentBlock[], options?: SendOptions): void
+  queue(content: ContentBlock[], options?: SendOptions): AgentMessageId
+
+  /**
+   * Submit steering into the running turn and request another step. An open turn
+   * records it at the next steering checkpoint before a request or continuation
+   * decision; policy may stop before another step. After turn close and its
+   * checkpoint, any remainder is queued for a later turn; terminal
+   * `agent/turn-stop`, cancellation, or disposal may discard it. Idle steering
+   * becomes a waking ordinary turn.
+   * @param content - the steering content blocks.
+   * @param options - source, attached contexts, and durable model-hidden meta.
+   * @returns the accepted message's {@link AgentMessageId}, stable across its `agent/inbox/*` events.
+   */
+  steer(content: ContentBlock[], options?: SendOptions): AgentMessageId
 
   /**
    * Append detached model-facing context without running the model. An open-turn
    * injection joins at the current log position unless the current tool batch is
-   * executing; then it waits FIFO until that batch settles and drains before turn
-   * close even when interrupted. Idle injection uses a one-shot turn and durability
-   * checkpoint. Disposal awaits idle checkpoints; flush failures report through `agent/error`.
+   * executing; then it waits FIFO until that batch settles and drains before
+   * turn close even when interrupted. Idle injection uses a one-shot turn and
+   * durability checkpoint. Disposal awaits idle checkpoints; flush failures
+   * report through `agent/error`. An omitted source defaults to
+   * `{ kind: 'plugin', plugin: '' }`.
+   * @param content - the injected context content blocks.
+   * @param options - source and durable model-hidden meta.
+   * @returns the accepted injection's {@link AgentMessageId}; injection emits no `agent/inbox/*` events.
    */
-  inject(content: ContentBlock[], options?: InjectOptions): void
+  inject(content: ContentBlock[], options?: InjectOptions): AgentMessageId
 
   /**
-   * Clear all queued and steering work, including items waiting to start, and
-   * abort the active turn. An effective call first emits
-   * `agent/cancel-requested` with the resolved typed cause. The first cause wins
-   * for the active turn, and `whenIdle()` resolves after cancellation reaches
-   * quiescence. Omission means `{ kind: 'user' }`. Idle cancellation is a no-op
-   * and does not arm later work. The active turn snapshots and freezes the cause.
-   * @param cause - the stable caller intent carried by the current turn signal.
+   * Accept one fully specified input through the same snapshot and routing path
+   * as the four intent-named helpers. `next-turn` targets the ordinary FIFO;
+   * `next-step`/wakeup targets steering (falling back to an ordinary waking turn
+   * while idle); and `next-step` without wakeup injects durable context without
+   * running the model. Every field is mandatory and no source or routing default
+   * is applied. Invalid input throws synchronously before notification, enqueue,
+   * or append.
+   * @param input - the resolved content, attribution, context, metadata, and routing facts.
+   * @returns the accepted input's {@link AgentMessageId}, carried by FIFO lifecycle events when applicable.
    */
-  cancel(cause?: AgentCancelCause): void
+  send(input: ResolvedAgentInput): AgentMessageId
+
+  /**
+   * Clear queued and steering work — unless `keepInbox` — and abort the active
+   * turn. An effective call first emits `agent/cancel-requested` with the
+   * resolved typed cause. The first cause wins for the active turn, and
+   * `whenIdle()` resolves after cancellation reaches quiescence. Omitted cause
+   * means `{ kind: 'user' }`. Idle cancellation is a no-op and does not arm
+   * later work. The active turn snapshots and freezes the cause.
+   * @param cause - the stable caller intent carried by the current turn signal.
+   * @param options - cancellation options; `keepInbox` preserves pending work.
+   */
+  cancel(cause?: AgentCancelCause, options?: CancelOptions): void
 
   /** Resolve at idle quiescence; disposal waits for driver exit rather than only the status transition. */
   whenIdle(): Promise<void>
-
 }
 ```
 
@@ -460,7 +570,7 @@ The process-local initiator carried by `ctx.agents` is the exact `Agent` above,
 
 ## Interception decisions
 
-Each `agent/*` interception waterfall returns a small, seam-specific typed union — the unified Decision idiom (the tool seams' `PreToolDecision`/`PostToolDecision` in [tools.md](tools.md) follow the same shape). A CC/Codex hook bridge maps its `permissionDecision`/`decision`/`continue`/`additionalContext` fields onto these; a native plugin returns them directly. Prompt and post-tool decisions share one model-facing context shape, `HookContext`, which carries a REQUIRED `source` (a missing source would default to `{kind:'user'}` and mislabel plugin context as a user prompt). Its `content` reaches the model verbatim as user-role input, while JSON `meta` persists plugin state without exposing it to the model. Absent or `separate` placement becomes `context/message`; `prompt-prefix` placement is available to prompt and steering inbox attachments and bakes the context before the effective request in the same message. Both decisions carry `additionalContexts[]` so every entry preserves its own provenance, metadata, and placement. Continuation reasons are steering messages instead and deliberately use the narrower content/source shape.
+Each `agent/*` interception waterfall returns a small, seam-specific typed union — the unified Decision idiom (the tool seams' `PreToolDecision`/`PostToolDecision` in [tools.md](tools.md) follow the same shape). A CC/Codex hook bridge maps its `permissionDecision`/`decision`/`continue`/`additionalContext` fields onto these; a native plugin returns them directly. Prompt and post-tool decisions share one model-facing context shape, `HookContext`, which carries a REQUIRED `source` (a missing source would default to `{kind:'user'}` and mislabel plugin context as a user prompt). Its `content` reaches the model verbatim as user-role input, while JSON `meta` persists plugin state without exposing it to the model. Absent or `separate` placement becomes an injected `user/message` (plugin/goal source); `prompt-prefix` placement is available to prompt and steering inbox attachments and bakes the context before the effective request in the same message. Both decisions carry `additionalContexts[]` so every entry preserves its own provenance, metadata, and placement. Continuation reasons are steering messages instead and deliberately use the narrower content/source shape.
 
 Source: [`packages/core/agent/src/types.ts`](../../packages/core/agent/src/types.ts)
 
@@ -470,8 +580,8 @@ interface HookContext {
   content: ContentBlock[]
   source: MessageSource
   /**
-   * Model placement. Absent or `separate` records an independent
-   * `context/message`; `prompt-prefix` prepends this context and a stable
+   * Model placement. Absent or `separate` records an independent injected
+   * `user/message`; `prompt-prefix` prepends this context and a stable
    * request delimiter to the same user-role message as its attached prompt.
    */
   placement?: 'separate' | 'prompt-prefix'

docs/core-data-structures/goal.md

@@ -69,7 +69,7 @@ interface GoalView extends GoalSnapshot {
 
 ## Durable changes
 
-Every mutation is a `context/message` whose metadata is either a complete snapshot or a clear tombstone. The version, metadata, goal source, and verbatim rendered content form one replay invariant.
+Every mutation is a round-zero goal-sourced `user/message` whose metadata is either a complete snapshot or a clear tombstone. The version, metadata, goal source, and verbatim rendered content form one replay invariant.
 
 ```ts type-equiv
 /** Full-snapshot goal mutation retained in a model-visible context event. */

docs/core-data-structures/session-reference.md

@@ -36,7 +36,7 @@ interface SessionReferenceCandidate {
 
 ## Prepared messages
 
-Preparation preserves readable current-message content and returns at most one aggregated context. The host binds `contexts` to that exact `send()` or `steer()` call.
+Preparation preserves readable current-message content and returns at most one aggregated context. The host binds `contexts` to that exact `followup()` or `steer()` call.
 
 ```ts type-equiv
 /** Message payload and the zero-or-one durable snapshot contexts bound to it. */

docs/core-data-structures/session.md

@@ -9,7 +9,13 @@ Source: [`packages/core/session/src/types.ts`](../../packages/core/session/src/t
 The append-only event types. Merge-extensible: a plugin declares extra event types via declaration merging — e.g. the [compaction seam](compaction.md) adds `compact/start` / `compact/summary` / `compact/end`, and `@deepseek-ai/dsh-hook-protocol` adds log-only `hook/invoked` / `hook/result` provenance for a hook bridge. Like `compact/*`, these are NOT `SurfaceEventType`s (no `surfaceOp`). The generated [persistence log event catalog](../persistence-catalog.md) enumerates every member — core and merged — with its payload, surface badge, and declaration site.
 
 ```ts type-equiv
-/** Shared payload for ordinary and steering prompt messages. */
+/**
+ * Shared payload for user, injected-context, and steering prompt messages. A
+ * direct human prompt, a synthetic `agent.inject()` context, and mid-turn
+ * steering all project into the model transcript as verbatim user-role content;
+ * they are told apart by `source` (a non-`user` kind marks injected context),
+ * not by event type. `meta` carries durable model-hidden producer state.
+ */
 interface PromptMessageData {
   /** Exact model-facing blocks, including any baked prompt-prefix contexts. */
   content: ContentBlock[]
@@ -17,6 +23,15 @@ interface PromptMessageData {
   source: MessageSource
   /** Present only when prompt-prefix contexts were baked into `content`. */
   envelope?: PromptMessageEnvelope
+  /**
+   * Opaque durable JSON state retained on the event but hidden from the model
+   * projection. It is the intended channel for a future framing directive (a
+   * producer declares the frame, a dedicated renderer applies it — see the
+   * deferred note in
+   * ../../../../.agents/notes/implemented/simplification/2026-07-20-unwrap-injected-content-envelopes.md),
+   * so the surface keeps projecting `content` verbatim rather than wrapping it.
+   */
+  meta?: JsonValue
 }
 ```
 
@@ -46,29 +61,21 @@ interface SessionEventMap {
   'step/start': { turn: number; step: number }
   /** Closes step `step` of turn `turn`. */
   'step/end': { turn: number; step: number }
-  /** A user-visible prompt (the queued message claimed for this turn). */
+  /**
+   * A user-role message on the model-visible surface: a direct human prompt
+   * (the queued message claimed for this turn), a synthetic `agent.inject()`
+   * context (file-change notices, subdir AGENTS.md, skill content, cron
+   * notifications, …), or an admitted goal continuation round. All three
+   * project their `content` verbatim; `source` (with a non-`user` kind marking
+   * injected context) is the only channel that tells them apart. An idle
+   * injection wraps this event in a one-shot turn so the log stays turn-enclosed.
+   */
   'user/message': PromptMessageData
   /**
    * Durable record of a prompt veto and its reason. It is log-only: the blocked
    * prompt never enters the model-visible surface, and its turn runs zero steps.
    */
   'prompt/blocked': { content: ContentBlock[]; source: MessageSource; reason: string }
-  /**
-   * In-session context injection (file-change notices, subdir AGENTS.md,
-   * skill content, cron notifications, …). Rendered into the derived history
-   * as a synthetic user-role message carrying `content` verbatim — NOT a
-   * user prompt. `meta` is durable JSON state omitted from the model
-   * projection; it is also the intended channel for any future framing
-   * directive (a producer declares the frame, a dedicated renderer applies it —
-   * see the deferred note in
-   * ../../../../.agents/notes/implemented/simplification/2026-07-20-unwrap-injected-content-envelopes.md),
-   * so the surface keeps projecting `content` verbatim rather than wrapping it.
-   */
-  'context/message': {
-    content: ContentBlock[]
-    source: MessageSource
-    meta?: JsonValue
-  }
   /** Raw stream chunk — token-level replay fidelity. */
   'assistant/chunk': { turn: number; step: number; chunk: StreamChunk }
   /**
@@ -199,7 +206,7 @@ A proper discriminated union over `type` (not independent `type`/`data` unions),
  *
  * The {@link sourceEventSeqs} and {@link surfaceOp} fields are conditional:
  * they only exist on {@link SurfaceEventType} variants (`user/message`,
- * `assistant/message`, `tool/result`, `context/message`, `steering/message`).
+ * `assistant/message`, `tool/result`, `steering/message`).
  * Non-surface events (boundary markers, chunks, usage, errors) never carry
  * surface metadata — the compiler enforces this at `Session.append()`
  * call sites.
@@ -233,7 +240,7 @@ For `assistant/message`, a present `sourceEventSeqs: []` is a complete known-emp
 
 ## Surface types
 
-The five message-producing types (`SurfaceEventType` — `user/message`, `assistant/message`, `tool/result`, `context/message`, `steering/message`) carry surface metadata declaring how they join the ordered derived surface. See the [session surface Agent Note](../../.agents/notes/implemented/architecture/2026-06-18-session-surface.md).
+The four message-producing types (`SurfaceEventType` — `user/message`, `assistant/message`, `tool/result`, `steering/message`) carry surface metadata declaring how they join the ordered derived surface. See the [session surface Agent Note](../../.agents/notes/implemented/architecture/2026-06-18-session-surface.md).
 
 ### `SurfaceEventType` — the message-producing subset of event types
 
@@ -247,7 +254,6 @@ type SurfaceEventType =
   | 'user/message'
   | 'assistant/message'
   | 'tool/result'
-  | 'context/message'
   | 'steering/message'
 ```
 
@@ -258,7 +264,7 @@ type SurfaceEventType =
  * How a session event entered the ordered surface. Only valid on
  * {@link SurfaceEventType} events.
  *
- * - `'append'`: added to the tail — normal path for user/assistant/tool/context
+ * - `'append'`: added to the tail — normal path for user/assistant/tool/steering
  *   messages.
  * - `{ op: 'replace', start, end }`: replaces surface nodes from `start`
  *   (inclusive) through `end` (inclusive) with this node. Both must exist as
@@ -465,7 +471,7 @@ declare class Session {
 - `user/message` → a user message carrying exact `content`; an optional envelope remains log-only display metadata.
 - `assistant/message` → an assistant message with the event's provider/model provenance and optional adapter-private replay state. Raw `assistant/chunk` events are replay/UI data and are **skipped** in derivation (the assembled message is authoritative). An **empty-content** `assistant/message` is also skipped — a max-tokens step cut off with no content still records an `assistant/message` to host its usage/provenance, but a content-less assistant turn must not enter the provider transcript.
 - `tool/result` → a user message carrying a `tool-result` block.
-- `context/message` → a user-role message carrying its `content` verbatim at its chronological position. Optional JSON `meta` remains in the event log and is never rendered.
+- `user/message` (injected context, i.e. non-`user` source) → a user-role message carrying its `content` verbatim at its chronological position. Optional JSON `meta` remains in the event log and is never rendered.
 - `steering/message` → a user-role message carrying exact `content` at its chronological position; an optional envelope remains log-only display metadata.
 
 Everything else (`turn/*`, `step/*`, plugin-owned `llm/retry`) is structural and does not project into a message. Token accounting reads per-step `assistant/chunk { type: 'usage' }` records and treats `assistant/message.usage` as the committed-step fallback when no usage chunk exists; failed model-request attempts have no assistant message, so their usage chunk is the durable accounting record. An operational error's step number is on `turn/end.reason` for `kind: 'error'`, with normalized `LlmFailure` facts for a final model-request failure and message/code for other live errors. Because this unreleased format intentionally has no compatibility promise, seed/load validation rejects request headers without provider+model and assistant messages without provider/model provenance instead of guessing a route for historical data.
@@ -489,11 +495,12 @@ interface TurnTriggerMap {
   message: { kind: 'message'; source: MessageSource }
   /**
    * An out-of-band context injection (`agent.inject()`) made while the agent
-   * was idle. The loop wraps the injected `context/message` in a one-shot turn
-   * (`turn/start` → `context/message` → `turn/end`) so every event in the log
-   * stays turn-enclosed — the durability/replay boundary is the turn, and a
-   * bare event between turns would otherwise be indistinguishable from a crash
-   * tail on reload.
+   * was idle. The loop wraps the injected `user/message` (a non-`user` source,
+   * plugin by default) in a one-shot turn (`turn/start` → `user/message` →
+   * `turn/end`) so every event in the log stays turn-enclosed — the
+   * durability/replay boundary is the turn, and a bare event between turns would
+   * otherwise be indistinguishable from a crash tail on reload. The trigger's
+   * `source` mirrors that message's producer.
    */
   injection: { kind: 'injection'; source: MessageSource }
 }
@@ -542,13 +549,13 @@ interface TurnEndReasonMap {
 
 ## The turn-enclosure invariant
 
-Every session event lives **inside** a turn (between a `turn/start` and its `turn/end`). The loop appends queued `user/message` events *after* `turn/start`, an idle `agent.inject()` wraps its `context/message` in a one-shot `injection` turn, and `appendOutOfBand()` similarly wraps an eligible log-only event when no turn is open. This makes the turn the single durability/replay boundary: a backend can treat anything after the last `turn/end` as an interrupted-crash tail without risking the loss of legitimately-recorded between-turn context. The optional `dsh-session/invariant` companion enforces it in dev through `ctx.invariants` (a message event outside an open turn throws). See [the turn-enclosure invariant Agent Note](../../.agents/notes/implemented/architecture/2026-06-15-turn-enclosure-invariant.md).
+Every session event lives **inside** a turn (between a `turn/start` and its `turn/end`). The loop appends queued `user/message` events *after* `turn/start`, an idle `agent.inject()` wraps its `user/message` in a one-shot `injection` turn, and `appendOutOfBand()` similarly wraps an eligible log-only event when no turn is open. This makes the turn the single durability/replay boundary: a backend can treat anything after the last `turn/end` as an interrupted-crash tail without risking the loss of legitimately-recorded between-turn context. The optional `dsh-session/invariant` companion enforces it in dev through `ctx.invariants` (a message event outside an open turn throws). See [the turn-enclosure invariant Agent Note](../../.agents/notes/implemented/architecture/2026-06-15-turn-enclosure-invariant.md).
 
 ## Plugin-contributed log-only events
 
 A plugin may declaration-merge extra `SessionEventMap` types. These are **log-only**: NOT `SurfaceEventType`s (they carry no `surfaceOp` and contribute nothing to derived history), but, like every event, they must sit inside an open turn. The full per-event enumeration — core and plugin-contributed alike, with payloads and provenance — is the generated [persistence log event catalog](../persistence-catalog.md); the compaction seam's `compact/*` semantics are discussed on [compaction.md](compaction.md).
 
-The hook bridges' `hook/invoked` / `hook/result` provenance pairs (from `@deepseek-ai/dsh-hook-protocol`) correlate by `handlerId`. The mid-turn hook points (`PreToolUse`/`PostToolUse`/`UserPromptSubmit`/`Stop`) fire inside the loop's open turn, so their `hook/*` records are turn-enclosed by construction. `SessionStart` gets no `hook/*` record — its injected `context/message` is the durable evidence — because it has no open turn to enclose one (see [the hook-bridges Agent Note](../../.agents/notes/implemented/feature/2026-06-30-hook-bridges.md)).
+The hook bridges' `hook/invoked` / `hook/result` provenance pairs (from `@deepseek-ai/dsh-hook-protocol`) correlate by `handlerId`. The mid-turn hook points (`PreToolUse`/`PostToolUse`/`UserPromptSubmit`/`Stop`) fire inside the loop's open turn, so their `hook/*` records are turn-enclosed by construction. `SessionStart` gets no `hook/*` record — its injected `user/message` is the durable evidence — because it has no open turn to enclose one (see [the hook-bridges Agent Note](../../.agents/notes/implemented/feature/2026-06-30-hook-bridges.md)).
 
 ## Durability contract