fix(plugin): normalize event session ids

Handle OpenCode session events that carry the session ID under properties.info.id or properties.info.sessionID so background tasks and continuation hooks do not miss idle/error/delete events.

Add regression coverage for nested session.idle events completing background tasks and waking continuation hooks.

src/hooks/claude-code-hooks/handlers/session-event-handler.ts

@@ -7,6 +7,7 @@ import { clearTranscriptCache } from "../transcript"
 import { clearToolInputCache, stopToolInputCacheCleanup } from "../tool-input-cache"
 import type { PluginConfig } from "../types"
 import { createInternalAgentTextPart, isHookDisabled, log } from "../../../shared"
+import { resolveSessionEventID } from "../../../shared/event-session-id"
 import {
 	clearAllSessionHookState,
 	clearSessionHookState,
@@ -26,7 +27,7 @@ export function createSessionEventHandler(
 
 		if (event.type === "session.error") {
 			const props = event.properties as Record<string, unknown> | undefined
-			const sessionID = props?.sessionID as string | undefined
+			const sessionID = resolveSessionEventID(props)
 			if (sessionID) {
 				sessionErrorState.set(sessionID, {
 					hasError: true,
@@ -38,13 +39,13 @@ export function createSessionEventHandler(
 
 		if (event.type === "session.deleted") {
 			const props = event.properties as Record<string, unknown> | undefined
-			const sessionInfo = props?.info as { id?: string } | undefined
-			if (sessionInfo?.id) {
-				parentSessionIdCache.delete(sessionInfo.id)
-				clearTranscriptCache(sessionInfo.id)
-				clearToolInputCache(sessionInfo.id)
-				contextCollector?.clear(sessionInfo.id)
-				clearSessionHookState(sessionInfo.id)
+			const sessionID = resolveSessionEventID(props)
+			if (sessionID) {
+				parentSessionIdCache.delete(sessionID)
+				clearTranscriptCache(sessionID)
+				clearToolInputCache(sessionID)
+				contextCollector?.clear(sessionID)
+				clearSessionHookState(sessionID)
 			}
 			return
 		}
@@ -54,7 +55,7 @@ export function createSessionEventHandler(
 		}
 
 		const props = event.properties as Record<string, unknown> | undefined
-		const sessionID = props?.sessionID as string | undefined
+		const sessionID = resolveSessionEventID(props)
 		if (!sessionID) return
 
 		const claudeConfig = await loadClaudeHooksConfig()