Merge remote-tracking branch 'origin/master' into codex/tool-json-schema-dsl

# Conflicts:
#	scripts/type-equiv.manifest.json

packages/core/session/src/index.ts

@@ -11,9 +11,9 @@ import { isAbsolute } from 'node:path'
 import { deepFreeze } from '@deepseek-ai/dsh-llm'
 import { scopeOf, scopeTarget } from '@deepseek-ai/dsh-scope'
 import type { Scoped } from '@deepseek-ai/dsh-scope'
-import type { Message } from '@deepseek-ai/dsh-llm'
+import type { ContentBlock, Message } from '@deepseek-ai/dsh-llm'
 import { SESSION_FORMAT_VERSION, SessionId } from './types.ts'
-import type { CreateSessionOptions, EpochHeader, OutOfBandSessionEventType, SessionEvent, SessionEventMap, SessionEventType, SessionHeader, SurfaceIntent, SurfaceEventType, TurnTrigger } from './types.ts'
+import type { CreateSessionOptions, EpochHeader, OutOfBandSessionEventType, PromptMessageData, SessionEvent, SessionEventMap, SessionEventType, SessionHeader, SurfaceIntent, SurfaceEventType, TurnTrigger } from './types.ts'
 import { snapshotJsonValue } from './json.ts'
 import { SurfaceManager } from './surface.ts'
 import type { SessionSurface } from './surface.ts'
@@ -29,6 +29,15 @@ export type { SessionSurface, SurfaceFoldReplacement, SurfaceFoldResult } from '
 export { foldSurface, isSurfaceEvent, isSurfaceEligibleType } from './surface.ts'
 export { canonicalHeader, foldRequestHeader, headerEquals } from './request-header.ts'
 
+/**
+ * Return the human-facing prompt blocks from a durable prompt message.
+ * @param data - ordinary or steering prompt event data.
+ * @returns the effective direct prompt, excluding baked prefix context.
+ */
+export function displayPromptContent(data: PromptMessageData): ContentBlock[] {
+  return data.envelope?.displayContent ?? data.content
+}
+
 /**
  * Find the latest closed message-triggered turn, excluding injection and
  * plugin-owned zero-step turns.
@@ -523,9 +532,11 @@ export class Session {
     // trace/replay data.
 
     switch (event.type) {
-      // Injected context and mid-turn steering project identically to a user
-      // prompt: content verbatim, in user role. context's `source`/`meta` and
-      // steering's `turn` are log-only and do not reach the model. Do NOT
+      // Injected context, ordinary prompts, and mid-turn steering project
+      // identically in user role: the event's model-facing content stays
+      // verbatim. A prompt envelope is model-hidden display metadata; its
+      // prefix bytes are already present in content. context's `source`/`meta`
+      // and steering's `turn` are also log-only. Do NOT
       // re-add per-type framing (e.g. `<context>`/`<steering>`) here: framing is
       // caller-owned — a producer bakes it into `content`, as workspace-context
       // does with `<system-reminder>` — or, if reintroduced, must be driven by

packages/core/session/src/types.ts

@@ -180,6 +180,37 @@ export interface EpochHeader {
  */
 export type RequestHeaderReason = 'initial' | 'resume' | 'change'
 
+/** Durable model-hidden annotation for one context baked into a prompt message. */
+export interface PromptPrefixContext {
+  /** Producer provenance retained for transcript presentation and inspection. */
+  source: MessageSource
+  /** Opaque JSON state retained in the session event but hidden from the model. */
+  meta?: JsonValue
+}
+
+/**
+ * Human-facing view of a prompt whose exact model content includes prefixed
+ * context. `content` on the owning event remains the reconstructable model
+ * input; this envelope prevents transcript, title, and re-reference consumers
+ * from treating the baked context as direct human text.
+ */
+export interface PromptMessageEnvelope {
+  /** Effective user prompt after interception rewrites, without baked context. */
+  displayContent: ContentBlock[]
+  /** Ordered descriptors for contexts already baked into the event content. */
+  prefixContexts: PromptPrefixContext[]
+}
+
+/** Shared payload for ordinary and steering prompt messages. */
+export interface PromptMessageData {
+  /** Exact model-facing blocks, including any baked prompt-prefix contexts. */
+  content: ContentBlock[]
+  /** Producer provenance for the direct prompt. */
+  source: MessageSource
+  /** Present only when prompt-prefix contexts were baked into `content`. */
+  envelope?: PromptMessageEnvelope
+}
+
 /**
  * The merge-extensible, append-only source of truth for an agent interaction.
  * Message history is derived from this log. Every event is lossless JSON and
@@ -206,7 +237,7 @@ export interface SessionEventMap {
   /** Closes step `step` of turn `turn`. */
   'step/end': { turn: number; step: number }
   /** A user-visible prompt (the queued message claimed for this turn). */
-  'user/message': { content: ContentBlock[]; source: MessageSource }
+  '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.
@@ -254,7 +285,7 @@ export interface SessionEventMap {
    */
   'tool/result': { turn: number; step: number; callId: CallId; content: ContentBlock[]; isError: boolean; error?: { name: string; code: string }; meta?: unknown }
   /** Steering content injected between steps of a running turn. */
-  'steering/message': { turn: number; content: ContentBlock[]; source: MessageSource }
+  'steering/message': PromptMessageData & { turn: number }
   /** Whole-list snapshot; latest write wins on replay. Log-only UI state; never derived history. */
   'todo/write': { todos: TodoItem[] }
   /**