Permission-wait and subagent spans (CL-5170)

src/perf/active-turn.ts

@@ -0,0 +1,22 @@
+/**
+ * Process-wide open-turn id for nesting permission.wait / subagent outside the
+ * reactor observer.
+ *
+ * Single-primary assumption: one run-sink observer owns the slot. A second
+ * concurrent observer overwrites the parent used by gate/task spans — not
+ * supported. `clear()`, observer `reset()`, and `closeTurn` null the slot.
+ */
+
+let activeTurnId: string | null = null;
+
+export function getActiveTurnId(): string | null {
+  return activeTurnId;
+}
+
+export function setActiveTurnId(id: string | null): void {
+  activeTurnId = id;
+}
+
+export function clearActiveTurnId(): void {
+  activeTurnId = null;
+}

src/perf/index.test.ts

@@ -243,6 +243,7 @@ describe("sanitizeTags", () => {
       provider_id: "openai",
       model_id: "gpt-5.4",
       transport: "ws",
+      decision: "allow",
       duration_ms: 12.5,
       bytes: 1024,
       payload_bytes: 2048,
@@ -257,6 +258,7 @@ describe("sanitizeTags", () => {
       provider_id: "openai",
       model_id: "gpt-5.4",
       transport: "ws",
+      decision: "allow",
       duration_ms: 12.5,
       bytes: 1024,
       payload_bytes: 2048,
@@ -269,6 +271,12 @@ describe("sanitizeTags", () => {
     });
   });
 
+  test("keeps decision allow/deny and strips free-text decisions", () => {
+    expect(sanitizeTags({ decision: "allow" })).toEqual({ decision: "allow" });
+    expect(sanitizeTags({ decision: "deny" })).toEqual({ decision: "deny" });
+    expect(sanitizeTags({ decision: "maybe" })).toBeUndefined();
+  });
+
   test("strips free-text, paths, prompts, and unknown keys", () => {
     const tags = sanitizeTags({
       prompt: "system: you are a helpful assistant",

src/perf/index.ts

@@ -11,13 +11,15 @@
  */
 
 import { isOpaqueId, sanitizeTags, type PerfTags } from "./sanitize.js";
+import { clearActiveTurnId } from "./active-turn.js";
 
 export {
   sanitizeTags,
   isOpaqueId,
   OPAQUE_ID_RE,
   ALLOWED_TAG_KEYS,
   type AllowedTagKey,
+  type DecisionKind,
   type PerfTags,
   type TransportKind,
 } from "./sanitize.js";
@@ -243,4 +245,6 @@ export function clear(): void {
   ringWrite = 0;
   ringCount = 0;
   nextId = 0;
+  clearActiveTurnId();
 }
+