fix(plugin): dedupe synthetic idle events

src/plugin/event.test.ts

@@ -391,7 +391,7 @@ describe("createEventHandler - idle deduplication", () => {
 		expect(spawnTmuxPane).toHaveBeenCalledTimes(1)
 	})
 
-	it("does NOT dedup real-idle-after-synthetic-idle within 500ms", async () => {
+	it("#given session.status already emitted a synthetic idle #when real session.idle follows immediately #then hooks run once", async () => {
 		//#given
 		const dispatchCalls: EventInput[] = []
 		const eventHandler = createIdleTrackingEventHandler(dispatchCalls)
@@ -415,11 +415,9 @@ describe("createEventHandler - idle deduplication", () => {
 		}))
 
 		//#then
-		expect(dispatchCalls).toHaveLength(2)
+		expect(dispatchCalls).toHaveLength(1)
 		expect(dispatchCalls[0]?.event.type).toBe("session.idle")
 		expect((dispatchCalls[0]?.event.properties as { sessionID?: string } | undefined)?.sessionID).toBe(sessionId)
-		expect(dispatchCalls[1]?.event.type).toBe("session.idle")
-		expect((dispatchCalls[1]?.event.properties as { sessionID?: string } | undefined)?.sessionID).toBe(sessionId)
 	})
 
 	it("#given idle recovery handles an interrupted tool turn #when session.idle arrives #then later idle hooks are skipped for that event", async () => {
@@ -619,7 +617,7 @@ describe("createEventHandler - idle deduplication", () => {
 		}
 	})
 
-	it("keeps other session dedup state untouched when bypassing synthetic-idle for current session", async () => {
+	it("keeps other session dedup state untouched when suppressing real-idle-after-synthetic-idle", async () => {
 		//#given
 		const originalDateNow = Date.now
 		let currentNow = 30_000
@@ -679,7 +677,7 @@ describe("createEventHandler - idle deduplication", () => {
 			}))
 
 			//#then
-			expect(dispatchedSessionIds).toEqual(["ses_a", "ses_b", "ses_a"])
+			expect(dispatchedSessionIds).toEqual(["ses_a", "ses_b"])
 		} finally {
 			Date.now = originalDateNow
 		}

src/plugin/event.ts

@@ -593,12 +593,6 @@ export function createEventHandler(args: {
         const emittedAt = recentSyntheticIdles.get(sessionID);
         if (emittedAt !== undefined && now - emittedAt < DEDUP_WINDOW_MS) {
           recentSyntheticIdles.delete(sessionID);
-          // Let real idle events through even when a synthetic idle fired moments earlier.
-          // OpenCode diagnostics expect a concrete session.idle event signal.
-          const lastAnyIdleAt = recentAnyIdles.get(sessionID);
-          if (lastAnyIdleAt === emittedAt) {
-            recentAnyIdles.delete(sessionID);
-          }
         }
       }
       const recovered = await recoverInterruptedToolResultsOnIdleEvent(input);