fix: don't treat SubagentStop as the agent turn boundary

packages/adapters/claude/src/hooks.ts

@@ -12,9 +12,13 @@ import { HOOK_SH } from "@middle/core";
  *   - `SessionStart` → `session.started` carries `session_id`/`transcript_path`
  *     and triggers the launch→drive transition.
  *   - `Stop` → `agent.stopped` is the turn boundary the workflow classifies.
- * `SubagentStop` also normalizes to `agent.stopped` (per the taxonomy); the
- * dispatcher correlates by session, so a subagent turn boundary is treated as a
- * stop signal for the session.
+ * `SubagentStop` maps to its own `agent.subagent-stopped` event — NOT
+ * `agent.stopped`. A subagent (e.g. an Explore agent the implementer spawned)
+ * finishing is not the *main* agent's turn boundary; the main agent is still
+ * working. Conflating the two let the first subagent's completion resolve
+ * `awaitStop`, which classified a `bare-stop` and tore the workflow down
+ * mid-research. `agent.subagent-stopped` is recorded but never resolves the
+ * stop awaiter.
  */
 const CLAUDE_EVENT_MAP: ReadonlyArray<[claudeEvent: string, normalized: NormalizedEvent]> = [
   ["SessionStart", "session.started"],
@@ -23,7 +27,7 @@ const CLAUDE_EVENT_MAP: ReadonlyArray<[claudeEvent: string, normalized: Normaliz
   ["PostToolUse", "tool.post"],
   ["Notification", "agent.notification"],
   ["Stop", "agent.stopped"],
-  ["SubagentStop", "agent.stopped"],
+  ["SubagentStop", "agent.subagent-stopped"],
   ["SessionEnd", "session.ended"],
 ];
 

packages/adapters/claude/test/adapter.test.ts

@@ -341,7 +341,7 @@ describe("installHooks", () => {
     expect(cmd("PostToolUse")).toBe(`"${abs}" tool.post`);
     expect(cmd("Notification")).toBe(`"${abs}" agent.notification`);
     expect(cmd("Stop")).toBe(`"${abs}" agent.stopped`);
-    expect(cmd("SubagentStop")).toBe(`"${abs}" agent.stopped`);
+    expect(cmd("SubagentStop")).toBe(`"${abs}" agent.subagent-stopped`);
     expect(cmd("SessionEnd")).toBe(`"${abs}" session.ended`);
   });
 

packages/core/src/events.ts

@@ -11,6 +11,7 @@ export type NormalizedEvent =
   | "tool.failed"
   | "agent.notification"
   | "agent.stopped"
+  | "agent.subagent-stopped"
   | "session.ended"
   | "rate-limit.detected";
 
@@ -28,6 +29,7 @@ export const NORMALIZED_EVENTS: readonly NormalizedEvent[] = [
   "tool.failed",
   "agent.notification",
   "agent.stopped",
+  "agent.subagent-stopped",
   "session.ended",
   "rate-limit.detected",
 ];

packages/dispatcher/test/hook-server.test.ts

@@ -68,6 +68,21 @@ describe("HookServer — Stop", () => {
     const payload = await pending;
     expect(payload.reason).toBe("turn-end");
   });
+
+  test("a subagent stop does NOT resolve awaitStop — only the main agent's Stop does", async () => {
+    // Regression: SubagentStop normalizes to agent.subagent-stopped, not
+    // agent.stopped. A spawned Explore agent finishing must not be mistaken for
+    // the main agent's turn boundary (which tore the workflow down mid-research).
+    const pending = server.awaitStop("middle-6", 300);
+    await postHook("agent.subagent-stopped", "middle-6", { reason: "subagent-done" });
+    // the subagent stop is accepted but does not satisfy the stop awaiter
+    await expect(pending).rejects.toThrow();
+
+    // the main agent's real Stop does resolve it
+    const next = server.awaitStop("middle-6", 1000);
+    await postHook("agent.stopped", "middle-6", { reason: "turn-end" });
+    expect((await next).reason).toBe("turn-end");
+  });
 });
 
 describe("HookServer — HMAC auth + event validation (with store)", () => {

planning/middle-management-build-spec.md

@@ -808,14 +808,15 @@ All adapters emit these. The hook script POSTs `{type, sessionName, payload}` to
 | `tool.post` | PostToolUse | command hook (success) |
 | `tool.failed` | PostToolUseFailure | command hook (failure) |
 | `agent.notification` | Notification | n/a |
-| `agent.stopped` | Stop / SubagentStop | turn-end hook |
+| `agent.stopped` | Stop | turn-end hook |
+| `agent.subagent-stopped` | SubagentStop | (subagent turn-end) |
 | `session.ended` | SessionEnd | shutdown hook |
 | `rate-limit.detected` | (synthetic from Stop) | (synthetic from Stop) |
 
 Two events are **load-bearing for dispatch**, not merely observational:
 
 - `session.started` carries `session_id` and `transcript_path` in its payload. It is how the dispatcher discovers the on-disk transcript at all, and it triggers the launch→drive transition (enter auto mode, confirm readiness, send the prompt).
-- `agent.stopped` is the turn boundary the workflow reacts to. Because the interactive process does not exit between turns, this — not a process exit — is the signal the dispatcher classifies (`classifyStop`).
+- `agent.stopped` is the turn boundary the workflow reacts to. Because the interactive process does not exit between turns, this — not a process exit — is the signal the dispatcher classifies (`classifyStop`). It is fired only by the **main** agent's Stop. A `SubagentStop` (e.g. an Explore agent the implementer spawned finishing) is **not** a main-agent turn boundary — the main agent is still working — so it maps to the separate, observational `agent.subagent-stopped` and never resolves the workflow's stop awaiter. Conflating the two would let the first subagent's completion classify a premature `bare-stop` and tear the dispatch down mid-work.
 
 The hook script is uniform across both: