fix: keep SDK subagent notifications local

docs/rfc/implemented/simplification/2026-06-20-unify-agent-and-session-id.md

@@ -28,7 +28,7 @@ The config-driven path keeps `agents[].id` as a stable configuration label, not
 
 - Agent create/resume and subagent creation carry one identity, and `Session` stores it in one place.
 - The creation transaction retains final-entry collision, exact-entry detach, rollback, and quiescence coverage without identity-specific lifecycle state.
-- ACP, stdio, hooks, bash ownership, persistence, and lineage use the shared `SessionId` directly. The ACP subagent backend uses the child server's returned session id as its run id; the ACP bridge verifies exact `Agent` ownership from the forward session map; and JSON-RPC caches only disposable-child parent lineage.
+- ACP, stdio, hooks, bash ownership, persistence, and lineage use the shared `SessionId` directly. The ACP subagent backend uses the child server's returned session id as its run id; the ACP bridge verifies exact `Agent` ownership from the forward session map; and JSON-RPC caches only local disposable-child parent lineage while leaving remote runs outside its local-session notification pair.
 - The config-driven resume-or-create policy is explicit and covered across a durable restart.
 - A production listener search kept `agent/created`/`agent/disposed` and their publication semantics.
 - Typecheck, coverage, snapshots, doc-sync, module-graph verification, build, and hygiene pass.

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`). 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`.
+`inject: ['agents']` — the server creates one agent per SDK `sessionId` (get-or-create on `session/prompt`). A local 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`. Runs from remote providers are not reported through this local-session notification pair because they create no local `session/created`/`subagent.started` edge. 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

@@ -104,8 +104,14 @@ export class HarnessSdkServer {
     }))
     this.disposers.push(ctx.on('subagent/end', (info: SubagentRunEndInfo) => {
       const agent = this.ctx.agents.get(info.id)
-      const parentSessionId = this.subagentParents.get(info.id) ?? agent?.session.header.parentSession
+      const cachedParentSessionId = this.subagentParents.get(info.id)
       this.subagentParents.delete(info.id)
+      // This protocol reports LOCAL child sessions, paired with the
+      // session/created-driven subagent.started notification above. A remote
+      // provider may use a real remote SessionId for its run, but that session
+      // does not exist in this harness and therefore has no paired start event.
+      if (cachedParentSessionId === undefined && agent === undefined) return
+      const parentSessionId = cachedParentSessionId ?? agent?.session.header.parentSession
       this.transport.notify('subagent.finished', {
         provider: info.provider,
         agentId: String(info.id),

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

@@ -303,7 +303,7 @@ describe('HarnessSdkServer', () => {
     }
   })
 
-  it('falls back to live lineage and treats the shared id as the child session id', async () => {
+  it('falls back to live lineage and ignores runs without a local child session', async () => {
     const storageDir = await mkdtemp(join(tmpdir(), 'dsh-jsonrpc-subagent-fallback-'))
     const ctx = await makeHarness(storageDir)
     let parentHandle: AgentHandle | undefined
@@ -367,16 +367,10 @@ describe('HarnessSdkServer', () => {
           stopReason: 'error',
         },
       })
-      expect(transport.notifications).toContainEqual({
+      expect(transport.notifications.some(n =>
-        method: 'subagent.finished',
+        n.method === 'subagent.finished'
-        params: {
+        && n.params?.agentId === 'missing-child-agent',
-          provider: 'fork',
+      )).toBe(false)
-          agentId: 'missing-child-agent',
-          childSessionId: 'missing-child-agent',
-          status: 'error',
-          stopReason: 'error',
-        },
-      })
 
       await server.shutdown()
     } finally {