refactor: remove UI identity translations

packages/ui/jsonrpc/README.md

@@ -4,7 +4,7 @@ The **SDK server plugin** (`jsonrpc`): mounting it serves a stdio JSON-RPC serve
 
 ## Wiring
 
-`inject: ['agents']` — the server creates one agent per SDK `sessionId` (get-or-create on `session/prompt`) and demuxes `subagent/end` through the registry. The LLM seam is read opportunistically via `ctx.get('llm')` (not injected): when `initialize.model` has no registered adapter, the plugin mounts `dsh-llm-deepseek` for it (credentials from `$DEEPSEEK_API_KEY` / `$DEEPSEEK_BASE_URL`); a config-registered adapter for the model wins. Everything else — persistence, the tool stacks, the adapter set — comes from the surrounding `cordis.yml`.
+`inject: ['agents']` — the server creates one agent per SDK `sessionId` (get-or-create on `session/prompt`). A subagent's shared agent/session id supplies `subagent.finished.childSessionId` directly; the server caches only parent lineage because the child may be disposed before `subagent/end`. The LLM seam is read opportunistically via `ctx.get('llm')` (not injected): when `initialize.model` has no registered adapter, the plugin mounts `dsh-llm-deepseek` for it (credentials from `$DEEPSEEK_API_KEY` / `$DEEPSEEK_BASE_URL`); a config-registered adapter for the model wins. Everything else — persistence, the tool stacks, the adapter set — comes from the surrounding `cordis.yml`.
 
 ## Config
 

packages/ui/jsonrpc/src/server.ts

@@ -58,11 +58,6 @@ interface SessionRecord {
   activePrompt: boolean
 }
 
-interface SubagentRecord {
-  childSessionId: string
-  parentSessionId: string | undefined
-}
-
 /**
  * The SDK server over a booted harness context. Constructing it subscribes to
  * the context's `session/event`, `session/created`, `agent/created`, and
@@ -76,7 +71,7 @@ export class HarnessSdkServer {
   private llmFiber: { dispose(): Promise<void> } | undefined
   private readonly sessions = new Map<string, SessionRecord>()
   private readonly sessionCreations = new Map<string, Promise<SessionRecord>>()
-  private readonly subagentSessions = new Map<string, SubagentRecord>()
+  private readonly subagentParents = new Map<SessionId, SessionId>()
   private readonly disposers: (() => void)[] = []
   private shutdownTask: Promise<Record<string, never>> | undefined
   private shuttingDown = false
@@ -100,29 +95,22 @@ export class HarnessSdkServer {
         childSessionId: String(session.id),
       })
     }))
-    // Cache agent → session lineage on creation: by the time `subagent/end`
-    // fires the child agent may already be disposed and gone from the registry.
+    // Cache parent lineage on creation: by the time `subagent/end` fires the
+    // child agent may already be disposed and gone from the registry. The child
+    // session id needs no cache because it is the shared agent/session id.
     this.disposers.push(ctx.on('agent/created', (agent) => {
-      this.subagentSessions.set(String(agent.id), {
-        childSessionId: String(agent.session.id),
-        parentSessionId: agent.session.header.parentSession === undefined
-          ? undefined
-          : String(agent.session.header.parentSession),
-      })
+      const parentSessionId = agent.session.header.parentSession
+      if (parentSessionId !== undefined) this.subagentParents.set(agent.id, parentSessionId)
     }))
     this.disposers.push(ctx.on('subagent/end', (info: SubagentRunEndInfo) => {
-      const rec = this.subagentSessions.get(String(info.id))
       const agent = this.ctx.agents.get(info.id)
-      const childSessionId = rec?.childSessionId ?? (agent === undefined ? undefined : String(agent.session.id))
-      const parentSessionId = rec?.parentSessionId ?? (
-        agent?.session.header.parentSession === undefined ? undefined : String(agent.session.header.parentSession)
-      )
-      if (childSessionId === undefined) return
+      const parentSessionId = this.subagentParents.get(info.id) ?? agent?.session.header.parentSession
+      this.subagentParents.delete(info.id)
       this.transport.notify('subagent.finished', {
         provider: info.provider,
         agentId: String(info.id),
-        ...(parentSessionId === undefined ? {} : { parentSessionId }),
-        childSessionId,
+        ...(parentSessionId === undefined ? {} : { parentSessionId: String(parentSessionId) }),
+        childSessionId: String(info.id),
         status: info.stopReason === 'completed' ? 'ok' : 'error',
         stopReason: info.stopReason,
         ...(info.lastAssistantMessage === undefined ? {} : { lastAssistantMessage: info.lastAssistantMessage }),
@@ -195,7 +183,7 @@ export class HarnessSdkServer {
     this.sessionCreations.clear()
     const records = [...this.sessions.values()]
     this.sessions.clear()
-    this.subagentSessions.clear()
+    this.subagentParents.clear()
     const failures: unknown[] = []
     while (this.disposers.length > 0) {
       try {

packages/ui/jsonrpc/tests/server.spec.ts

@@ -272,6 +272,9 @@ describe('HarnessSdkServer', () => {
         meta: { cwd: storageDir, parentSession: SessionId('main') },
         agentOptions: { model: 'deepseek' },
       })
+      // The backend may dispose the child before publishing its run outcome;
+      // only the cached parent lineage should be needed at this point.
+      await handle.dispose()
       await settleSubagent(ctx, parentHandle.agent, {
         provider: 'spawn',
         id: SessionId('child-session'),
@@ -292,7 +295,6 @@ describe('HarnessSdkServer', () => {
         },
       })
 
-      await handle.dispose()
       await parentHandle.dispose()
       await server.shutdown()
     } finally {
@@ -301,7 +303,7 @@ describe('HarnessSdkServer', () => {
     }
   })
 
-  it('falls back to live agent lineage for uncached subagent end events', async () => {
+  it('falls back to live lineage and treats the shared id as the child session id', async () => {
     const storageDir = await mkdtemp(join(tmpdir(), 'dsh-jsonrpc-subagent-fallback-'))
     const ctx = await makeHarness(storageDir)
     let parentHandle: AgentHandle | undefined
@@ -365,10 +367,16 @@ describe('HarnessSdkServer', () => {
           stopReason: 'error',
         },
       })
-      expect(transport.notifications.some(n =>
-        n.method === 'subagent.finished'
-        && n.params?.agentId === 'missing-child-agent',
-      )).toBe(false)
+      expect(transport.notifications).toContainEqual({
+        method: 'subagent.finished',
+        params: {
+          provider: 'fork',
+          agentId: 'missing-child-agent',
+          childSessionId: 'missing-child-agent',
+          status: 'error',
+          stopReason: 'error',
+        },
+      })
 
       await server.shutdown()
     } finally {