chore(vendor): import pi 0.85.1

Imported as a linear vendor commit so forge rebases do not replay the upstream root tree.

git-subtree-dir: third_party/pi

git-subtree-split: d981de1229ef899957bbe968bc8dcda02a21f477

third_party/pi/packages/ai/src/session-resources.ts

@@ -0,0 +1,24 @@
+export type SessionResourceCleanup = (sessionId?: string) => void;
+
+const sessionResourceCleanups = new Set<SessionResourceCleanup>();
+
+export function registerSessionResourceCleanup(cleanup: SessionResourceCleanup): () => void {
+	sessionResourceCleanups.add(cleanup);
+	return () => {
+		sessionResourceCleanups.delete(cleanup);
+	};
+}
+
+export function cleanupSessionResources(sessionId?: string): void {
+	const errors: unknown[] = [];
+	for (const cleanup of sessionResourceCleanups) {
+		try {
+			cleanup(sessionId);
+		} catch (error) {
+			errors.push(error);
+		}
+	}
+	if (errors.length > 0) {
+		throw new AggregateError(errors, "Failed to cleanup session resources");
+	}
+}