feat: add scoped history and artifacts

src/chat/response-inputs.ts

@@ -1,5 +1,5 @@
 export type InputDelivery = "steer" | "queue";
-export type ResponseInput = { id: string; text: string; delivery: InputDelivery; status: "pending" | "delivered" };
+export type ResponseInput = { id: string; text: string; delivery: InputDelivery; status: "pending" | "delivered" | "cancelled" };
 type InboxRuntime = {
   enqueueUserInput: (sessionId: string, input: ResponseInput) => Promise<void>;
   listPendingUserInputs: (sessionId: string) => Promise<ResponseInput[]>;
@@ -19,7 +19,7 @@ export class ResponseInputTracker {
 
   markReady() { this.releaseReady(); }
   close() { this.accepting = false; this.releaseReady(); }
-  get hasAdditionalInput() { return this.items.size > 0; }
+  get hasAdditionalInput() { return [...this.items.values()].some((input) => input.status !== "cancelled"); }
 
   async restore() {
     for (const input of await this.runtime.listPendingUserInputs(this.sessionId)) this.items.set(input.id, input);
@@ -53,8 +53,9 @@ export class ResponseInputTracker {
 
   observe(type: string, data: { inboxID?: string; delivery?: InputDelivery }) {
     const input = data.inboxID ? this.items.get(data.inboxID) : undefined;
-    if (!input) return;
+    if (!input || input.status !== "pending") return;
     if (type === "session.inbox.delivered") input.status = "delivered";
+    else if (type === "session.inbox.cancelled") input.status = "cancelled";
     else if (type === "session.inbox.delivery.changed" && data.delivery) input.delivery = data.delivery;
     else return;
     this.changed({ ...input });