refactor(agent): remove message metadata channel

packages/context/session-reference/README.md

@@ -12,7 +12,7 @@
 
 Preparation calls `ctx.sessionQuery.readSurface()` once per distinct source and never rereads it after enqueue. It projects only direct-user `user/message`, direct-user `steering/message`, assistant text, and `user/message` checkpoints carrying the canonical `dsh-compact` source marker from the folded current surface. For a source prompt that already contains baked prefix context, projection reads only its model-hidden display content, preventing recursive snapshot propagation. Shadowed pre-compaction events, tools, reasoning, context, plugin-generated user messages other than marked compact checkpoints, and unfinished assistant chunks are excluded. A compacted source therefore contributes its latest checkpoint plus retained later conversation, not restored shadowed text.
 
-The context source is `{ kind: 'plugin', plugin: 'session-reference' }` with `placement: 'prompt-prefix'`. Its metadata records version `1`, source ids and labels, capture seqs, compact presence, retained/omitted message counts, omitted UTF-8 bytes, and truncation state. AgentLoop writes the snapshot, `## My request:` delimiter, and effective prompt into one `user/message` or `steering/message`; the same event's model-hidden envelope retains the direct prompt and metadata for TUI/ACP replay. Later source mutation, compaction, or deletion cannot change target replay.
+The context uses a typed `{ kind: 'session-reference', ... }` source with `placement: 'prompt-prefix'`. That source records version `1`, source ids and labels, capture seqs, compact presence, retained/omitted message counts, omitted UTF-8 bytes, and truncation state. AgentLoop writes the snapshot, `## My request:` delimiter, and effective prompt into one `user/message` or `steering/message`; the same event's model-hidden envelope retains the direct prompt and source for TUI/ACP replay. Later source mutation, compaction, or deletion cannot change target replay.
 
 ## Configuration
 

packages/context/session-reference/src/index.ts

@@ -9,7 +9,7 @@ import { Context, Service } from 'cordis'
 import z from 'schemastery'
 import type { Agent, HookContext } from '@deepseek-ai/dsh-agent'
 import type { ContentBlock } from '@deepseek-ai/dsh-llm'
-import type { JsonValue, SessionId } from '@deepseek-ai/dsh-session'
+import type { SessionId } from '@deepseek-ai/dsh-session'
 import type { SessionSurfaceSnapshot } from '@deepseek-ai/dsh-session-query'
 import {
   DEFAULT_CANDIDATE_LIMIT,
@@ -20,7 +20,7 @@ import {
 } from './config.ts'
 import { retainReferencedSession, type ReferenceRetentionStats, type ReferencedSessionData } from './projection.ts'
 import { stringifyTagSafeJson } from './serialization.ts'
-import type { PreparedReferencedMessage, SessionReferenceCandidate, SessionReferenceInput } from './types.ts'
+import type { PreparedReferencedMessage, SessionReferenceCandidate, SessionReferenceInput, SessionReferenceSource } from './types.ts'
 
 export type * from './types.ts'
 export type { Config, SessionReferenceErrorCode } from './config.ts'
@@ -181,7 +181,7 @@ export class SessionReferenceService extends Service {
 
     const rendered = this.renderSources(prepared)
     const prompt = renderPrompt(rendered.map(source => source.data))
-    const meta = {
+    const source: SessionReferenceSource = {
       kind: 'session-reference',
       version: 1,
       references: rendered.map((source, index) => ({
@@ -191,12 +191,11 @@ export class SessionReferenceService extends Service {
         ...source.stats,
         inputIndex: index,
       })),
-    } satisfies JsonValue
+    }
     const context: HookContext = {
-      source: { kind: 'plugin', plugin: 'session-reference' },
+      source,
       content: [{ type: 'text', text: prompt }],
       placement: 'prompt-prefix',
-      meta,
     }
     return { content: acceptedContent, contexts: [context] }
   }

packages/context/session-reference/src/types.ts

@@ -4,6 +4,30 @@ import type { HookContext } from '@deepseek-ai/dsh-agent'
 import type { ContentBlock } from '@deepseek-ai/dsh-llm'
 import type { SessionId } from '@deepseek-ai/dsh-session'
 
+/** Durable provenance for one prepared cross-session context. */
+export interface SessionReferenceSource {
+  kind: 'session-reference'
+  version: 1
+  references: {
+    sessionId: string
+    label: string
+    capturedThroughSeq: number | null
+    compacted: boolean
+    originalMessages: number
+    retainedMessages: number
+    omittedMessages: number
+    omittedBytes: number
+    truncated: boolean
+    inputIndex: number
+  }[]
+}
+
+declare module '@deepseek-ai/dsh-llm' {
+  interface MessageSourceMap {
+    'session-reference': SessionReferenceSource
+  }
+}
+
 /** One source session selected by a host. */
 export interface SessionReferenceInput {
   /** Opaque source session identity. */

packages/context/session-reference/tests/session-reference.spec.ts

@@ -241,7 +241,7 @@ describe('session reference discovery and preparation', () => {
     expect(prepared.contexts).toHaveLength(1)
     const context = prepared.contexts[0]
     if (context?.content[0]?.type !== 'text') throw new Error('expected text context')
-    expect(context.source).toEqual({ kind: 'plugin', plugin: 'session-reference' })
+    expect(context.source).toMatchObject({ kind: 'session-reference' })
     expect(context.placement).toBe('prompt-prefix')
     expect(context.content[0].text).toContain('untrusted, read-only snapshot')
     expect(promptData(context.content[0].text)).toEqual([{
@@ -256,7 +256,7 @@ describe('session reference discovery and preparation', () => {
         { role: 'assistant', text: 'visible answer' },
       ],
     }])
-    expect(context.meta).toMatchObject({
+    expect(context.source).toMatchObject({
       kind: 'session-reference',
       version: 1,
       references: [{
@@ -354,7 +354,7 @@ describe('session reference discovery and preparation', () => {
       { sessionId: one.id, label: 'first' },
       { sessionId: one.id, label: 'ignored duplicate' },
       { sessionId: two.id },
-    ])).resolves.toMatchObject({ contexts: [{ meta: { references: [{ label: 'first' }, { label: 'two' }] } }] })
+    ])).resolves.toMatchObject({ contexts: [{ source: { references: [{ label: 'first' }, { label: 'two' }] } }] })
     await expect(ctx.sessionReferences.prepare(agent, content, [{ sessionId: target.id }]))
       .rejects.toThrow(expectCode('SESSION_REFERENCE_SELF_REFERENCE'))
     await expect(ctx.sessionReferences.prepare(agent, content, [null as never]))
@@ -432,7 +432,7 @@ describe('session reference discovery and preparation', () => {
     expect(context.content[0].text).toContain('checkpoint')
     expect(context.content[0].text).toContain('latest-')
     expect(context.content[0].text).toContain('omitted')
-    expect(context.meta).toMatchObject({ references: [{ truncated: true, compacted: true }] })
+    expect(context.source).toMatchObject({ references: [{ truncated: true, compacted: true }] })
   })
 
   it('applies the full byte limit independently to each of three references', async () => {
@@ -501,7 +501,6 @@ describe('session reference discovery and preparation', () => {
         displayContent: prepared.content,
         prefixContexts: [{
           source: context.source,
-          ...context.meta === undefined ? {} : { meta: context.meta },
         }],
       },
     }, { surfaceOp: 'append' })