fix(coding-agent): abort stuck context hooks

closes #6234

packages/coding-agent/CHANGELOG.md

@@ -9,6 +9,7 @@
 
 ### Fixed
 
+- Fixed Escape aborts to clear runs stuck in extension context hooks that ignore abort signals ([#6234](https://github.com/earendil-works/pi/issues/6234)).
 - Fixed the question extension example to run question tool calls sequentially so multiple questions in one assistant turn remain answerable ([#6189](https://github.com/earendil-works/pi/issues/6189)).
 - Fixed `/login` to report auth storage persistence failures instead of claiming credentials were saved when `auth.json` is locked ([#6223](https://github.com/earendil-works/pi/issues/6223)).
 - Fixed split-turn compaction to serialize summary requests so single-concurrency local providers do not fail with 429 errors ([#5536](https://github.com/earendil-works/pi/issues/5536)).

packages/coding-agent/src/core/extensions/runner.ts

@@ -114,6 +114,25 @@ interface BeforeAgentStartCombinedResult {
 	systemPrompt?: string;
 }
 
+async function callContextHandlerAbortable<T>(fn: () => Promise<T> | T, signal: AbortSignal): Promise<T> {
+	if (signal.aborted) {
+		throw new Error("Agent run aborted");
+	}
+
+	let cleanup = () => {};
+	const abortPromise = new Promise<never>((_resolve, reject) => {
+		const onAbort = () => reject(new Error("Agent run aborted"));
+		signal.addEventListener("abort", onAbort, { once: true });
+		cleanup = () => signal.removeEventListener("abort", onAbort);
+	});
+
+	try {
+		return await Promise.race([Promise.resolve().then(fn), abortPromise]);
+	} finally {
+		cleanup();
+	}
+}
+
 /**
  * Events handled by the generic emit() method.
  * Events with dedicated emitXxx() methods are excluded for stronger type safety.
@@ -924,6 +943,7 @@ export class ExtensionRunner {
 
 	async emitContext(messages: AgentMessage[]): Promise<AgentMessage[]> {
 		const ctx = this.createContext();
+		const signal = ctx.signal;
 		let currentMessages = structuredClone(messages);
 
 		for (const ext of this.extensions) {
@@ -933,12 +953,17 @@ export class ExtensionRunner {
 			for (const handler of handlers) {
 				try {
 					const event: ContextEvent = { type: "context", messages: currentMessages };
-					const handlerResult = await handler(event, ctx);
+					const handlerResult = signal
+						? await callContextHandlerAbortable(() => handler(event, ctx), signal)
+						: await handler(event, ctx);
 
 					if (handlerResult && (handlerResult as ContextEventResult).messages) {
 						currentMessages = (handlerResult as ContextEventResult).messages!;
 					}
 				} catch (err) {
+					if (signal?.aborted) {
+						throw err;
+					}
 					const message = err instanceof Error ? err.message : String(err);
 					const stack = err instanceof Error ? err.stack : undefined;
 					this.emitError({