fix(coding-agent): read the settled turn from agent_end for error notifications

Classifier-refusal failures end a turn with stopReason === "error" but
get pruned from the active context (agent-session.ts's
#removeAssistantMessageFromActiveContext) before agent_end fires.
sendErrorNotification() read viewSession.getLastAssistantMessage(),
which reflects that mutated context and silently missed the
notification for exactly the turns it should fire on.

Thread the agent_end event through #handleAgentEnd -> #finishAgentEnd
so sendErrorNotification reads the turn's own outcome from
agent_end.messages instead.

packages/coding-agent/src/modes/controllers/event-controller.ts

@@ -1,4 +1,4 @@
-import type { ImageContent } from "@oh-my-pi/pi-ai";
+import type { AssistantMessage, ImageContent } from "@oh-my-pi/pi-ai";
 import * as AIError from "@oh-my-pi/pi-ai/error";
 import { getStreamingPartialJson } from "@oh-my-pi/pi-ai/utils/block-symbols";
 import { type Component, Loader, TERMINAL } from "@oh-my-pi/pi-tui";
@@ -1060,7 +1060,7 @@ export class EventController {
 			}
 		}
 	}
-	async #handleAgentEnd(_event: Extract<AgentSessionEvent, { type: "agent_end" }>): Promise<void> {
+	async #handleAgentEnd(event: Extract<AgentSessionEvent, { type: "agent_end" }>): Promise<void> {
 		// A superseded agent_end: the agent is already streaming a fresh turn, so
 		// this event belongs to a turn that has already been replaced. The session
 		// dispatches to listeners fire-and-forget across an async extension-emit hop
@@ -1072,10 +1072,10 @@ export class EventController {
 		// then). Mirrors the collab guest's !isStreaming loader reconciler.
 		if (this.ctx.session.isStreaming) return;
 
-		await this.#finishAgentEnd();
+		await this.#finishAgentEnd(event);
 	}
 
-	async #finishAgentEnd(): Promise<void> {
+	async #finishAgentEnd(event: Extract<AgentSessionEvent, { type: "agent_end" }>): Promise<void> {
 		this.#setTerminalProgress(false);
 		this.ctx.statusLine.markActivityEnd();
 		this.#streamingReveal.stop();
@@ -1120,7 +1120,7 @@ export class EventController {
 		this.ctx.ui.requestRender();
 		this.#scheduleIdleCompaction();
 		this.#scheduleIdleRecap();
-		this.sendErrorNotification();
+		this.sendErrorNotification(event);
 		this.sendCompletionNotification();
 	}
 
@@ -1477,11 +1477,17 @@ export class EventController {
 		return this.ctx.viewSession.getContextUsage()?.tokens ?? 0;
 	}
 
-	sendErrorNotification(): void {
+	sendErrorNotification(event: Extract<AgentSessionEvent, { type: "agent_end" }>): void {
 		const notify = settings.get("error.notify");
 		if (notify === "off") return;
 
-		const last = this.ctx.viewSession.getLastAssistantMessage?.();
+		// Read the turn's own outcome from `agent_end.messages`, not the mutable
+		// active context: a classifier-refusal failure is final (stopReason ===
+		// "error") but gets pruned from `viewSession`'s active context before this
+		// handler runs (see `#removeAssistantMessageFromActiveContext` in
+		// agent-session.ts), so `getLastAssistantMessage()` would see a stale or
+		// absent assistant and silently drop the notification.
+		const last = event.messages.findLast((message): message is AssistantMessage => message.role === "assistant");
 		if (last?.stopReason !== "error") return;
 
 		const sessionName = this.ctx.sessionManager.getSessionName();