feat(pi): drain and resume pi() runs

packages/pi/src/actions.ts

@@ -149,15 +149,11 @@ export function createPiActions(options: PiSessionOptions): PiActions {
 				await reloadCredentials(handle);
 				const { session } = handle;
 				requireCredential(session);
-				const abort = () => void session.abort();
-				c.abortSignal.addEventListener("abort", abort, { once: true });
-				try {
-					await traceRun(session, c.actorId, () =>
-						session.prompt(text, promptOptions),
-					);
-				} finally {
-					c.abortSignal.removeEventListener("abort", abort);
-				}
+				// The run outlives this action: a timeout, a caller that leaves, or
+				// a stopping actor never aborts it. Only the abort action does.
+				await traceRun(session, c.actorId, () =>
+					session.prompt(text, promptOptions),
+				);
 			}),
 		steer: (c, ...args) => mutate(c, ({ session }) => session.steer(...args)),
 		followUp: (c, ...args) =>

packages/pi/src/actor-types.ts

@@ -0,0 +1,31 @@
+/** `Omit` that keeps each member of a union, so `state` and `createState` stay alternatives. */
+export type DistributiveOmit<T, K extends PropertyKey> = T extends unknown
+	? Omit<T, K>
+	: never;
+
+/** The app's actions as clients see them: the same arguments, without `c.pi`. */
+export type ClientActions<T, TContext> = string extends keyof T
+	? Record<never, never>
+	: {
+			[K in keyof T]: T[K] extends (
+				c: any,
+				...args: infer TArgs
+			) => infer TResult
+				? (c: TContext, ...args: TArgs) => TResult
+				: ClientActions<T[K], TContext>;
+		};
+
+/** Wraps each of the app's actions, including nested ones, so it runs inside `run`. */
+export function wrapActions(
+	actions: Record<string, unknown>,
+	run: (c: any, action: () => unknown) => Promise<unknown>,
+): Record<string, unknown> {
+	return Object.fromEntries(
+		Object.entries(actions).map(([name, action]) => [
+			name,
+			typeof action === "function"
+				? (c: unknown, ...args: unknown[]) => run(c, () => action(c, ...args))
+				: wrapActions(action as Record<string, unknown>, run),
+		]),
+	);
+}