fix: distinguish explicit cancellation from ACP transport shutdown

dist/server.js

@@ -4420,12 +4420,10 @@ async function setupV2(context) {
             const pursue = command.action === "resume" || command.action === "goal" && args !== "" && !controlOnly;
             const signal = execution?.signal ? AbortSignal.any([abortController.signal, execution.signal]) : abortController.signal;
             let admitted = false;
-            let cancellation;
             const cancel = () => {
               if (!pursue || disposed)
                 return;
               goalServices.stopAutonomy?.(input.sessionID);
-              cancellation = cancelActiveGoal(input.sessionID).catch((error) => v2ErrorLog("Failed to persist command cancellation", error));
             };
             execution?.signal?.addEventListener("abort", cancel, { once: true });
             try {
@@ -4470,7 +4468,6 @@ async function setupV2(context) {
               }
             } finally {
               execution?.signal?.removeEventListener("abort", cancel);
-              await cancellation;
             }
           }
         });
@@ -4503,6 +4500,18 @@ async function setupV2(context) {
       }
     }));
   }
+  try {
+    const hookInterrupt = context.session.hook;
+    registrations.push(await hookInterrupt("interrupt", async ({ sessionID }) => {
+      markSessionOwnership(sessionID, true);
+      goalServices.stopAutonomy?.(sessionID);
+      try {
+        await cancelActiveGoal(sessionID);
+      } catch (error) {
+        v2ErrorLog("Failed to persist explicit session cancellation", error);
+      }
+    }));
+  } catch {}
   registrations.push(await context.tool.transform((draft) => {
     for (const tool of goalToolsV2(goalServices))
       draft.add(tool);

src/server.ts

@@ -2969,13 +2969,10 @@ async function setupV2(context: PluginV2.Plugin.Context): Promise<PluginV2.Plugi
                 ? AbortSignal.any([abortController.signal, execution.signal])
                 : abortController.signal
               let admitted = false
-              let cancellation: Promise<unknown> | undefined
               const cancel = () => {
                 if (!pursue || disposed) return
                 goalServices.stopAutonomy?.(input.sessionID)
-                cancellation = cancelActiveGoal(input.sessionID).catch((error) =>
-                  v2ErrorLog("Failed to persist command cancellation", error),
-                )
+                // Transport disposal stops local autonomy without closing the goal.
               }
               execution?.signal?.addEventListener("abort", cancel, { once: true })
               try {
@@ -3024,7 +3021,6 @@ async function setupV2(context: PluginV2.Plugin.Context): Promise<PluginV2.Plugi
                 }
               } finally {
                 execution?.signal?.removeEventListener("abort", cancel)
-                await cancellation
               }
             },
           })
@@ -3069,6 +3065,26 @@ async function setupV2(context: PluginV2.Plugin.Context): Promise<PluginV2.Plugi
     )
   }
 
+  // New hosts notify explicit user interruption even between execution cycles.
+  // Older hosts retain their execution-interrupted event handling.
+  try {
+    const hookInterrupt = context.session.hook as (
+      name: "interrupt",
+      callback: (event: { sessionID: string }) => Promise<void>,
+    ) => Promise<{ dispose(): Promise<void> }>
+    registrations.push(await hookInterrupt("interrupt", async ({ sessionID }) => {
+      markSessionOwnership(sessionID, true)
+      goalServices.stopAutonomy?.(sessionID)
+      try {
+        await cancelActiveGoal(sessionID)
+      } catch (error) {
+        v2ErrorLog("Failed to persist explicit session cancellation", error)
+      }
+    }))
+  } catch {
+    // Host predates the explicit session interruption hook.
+  }
+
   registrations.push(
     await context.tool.transform((draft) => {
       for (const tool of goalToolsV2(goalServices)) draft.add(tool)

test/server-v2.test.ts

@@ -1807,6 +1807,7 @@ test("V2 cleanup disposes registrations and stops the event consumer", async ()
     expect.arrayContaining([
       "command.transform",
       "session.hook:prompt",
+      "session.hook:interrupt",
       "tool.transform",
       "tool.hook:execute.before",
       "tool.hook:execute.after",
@@ -2465,6 +2466,7 @@ test("V2 command cancellation between idle cycles persists cancellation and stop
       { signal: controller.signal },
     )
   await waitFor(() => waits > 0)
+  await mock.hooks.interrupt!({ sessionID: "ses_v2" })
   controller.abort()
   await command
   expect((await getGoal("ses_v2"))?.status).toBe("cancelled")
@@ -2524,3 +2526,17 @@ test("V2 a stopped event stream pauses a waiting goal rather than polling foreve
     .execute({ sessionID: "ses_v2", prompt: { text: "Continue the goal" }, delivery: "steer" })
   expect((await getGoal("ses_v2"))?.status).toBe("paused")
 })
+
+test("V2 a command transport abort preserves the active goal for reconnection", async () => {
+  const mock = makeMockContext()
+  let waits = 0
+  const context = { ...mock, session: { ...mock.session, wait: async () => { waits++ } } }
+  await setupPlugin(context as never)
+  await createGoalViaV2Tool(mock, "Preserve scope after disconnect")
+  const controller = new AbortController()
+  const command = mock.commands.find((command) => command.name === "goal")!.execute({ sessionID: "ses_v2", prompt: { text: "Preserve scope after disconnect" }, delivery: "steer" }, { signal: controller.signal })
+  await waitFor(() => waits > 0)
+  controller.abort()
+  await command
+  expect((await getGoal("ses_v2"))?.status).toBe("active")
+})