fix: preserve inter-session input provenance (thanks @anbecker)

src/sessions/input-provenance.ts

@@ -0,0 +1,79 @@
+import type { AgentMessage } from "@mariozechner/pi-agent-core";
+
+export const INPUT_PROVENANCE_KIND_VALUES = [
+  "external_user",
+  "inter_session",
+  "internal_system",
+] as const;
+
+export type InputProvenanceKind = (typeof INPUT_PROVENANCE_KIND_VALUES)[number];
+
+export type InputProvenance = {
+  kind: InputProvenanceKind;
+  sourceSessionKey?: string;
+  sourceChannel?: string;
+  sourceTool?: string;
+};
+
+function normalizeOptionalString(value: unknown): string | undefined {
+  if (typeof value !== "string") {
+    return undefined;
+  }
+  const trimmed = value.trim();
+  return trimmed ? trimmed : undefined;
+}
+
+function isInputProvenanceKind(value: unknown): value is InputProvenanceKind {
+  return (
+    typeof value === "string" && (INPUT_PROVENANCE_KIND_VALUES as readonly string[]).includes(value)
+  );
+}
+
+export function normalizeInputProvenance(value: unknown): InputProvenance | undefined {
+  if (!value || typeof value !== "object") {
+    return undefined;
+  }
+  const record = value as Record<string, unknown>;
+  if (!isInputProvenanceKind(record.kind)) {
+    return undefined;
+  }
+  return {
+    kind: record.kind,
+    sourceSessionKey: normalizeOptionalString(record.sourceSessionKey),
+    sourceChannel: normalizeOptionalString(record.sourceChannel),
+    sourceTool: normalizeOptionalString(record.sourceTool),
+  };
+}
+
+export function applyInputProvenanceToUserMessage(
+  message: AgentMessage,
+  inputProvenance: InputProvenance | undefined,
+): AgentMessage {
+  if (!inputProvenance) {
+    return message;
+  }
+  if ((message as { role?: unknown }).role !== "user") {
+    return message;
+  }
+  const existing = normalizeInputProvenance((message as { provenance?: unknown }).provenance);
+  if (existing) {
+    return message;
+  }
+  return {
+    ...(message as unknown as Record<string, unknown>),
+    provenance: inputProvenance,
+  } as unknown as AgentMessage;
+}
+
+export function isInterSessionInputProvenance(value: unknown): boolean {
+  return normalizeInputProvenance(value)?.kind === "inter_session";
+}
+
+export function hasInterSessionUserProvenance(
+  message: { role?: unknown; provenance?: unknown } | undefined,
+): boolean {
+  if (!message || message.role !== "user") {
+    return false;
+  }
+  return isInterSessionInputProvenance(message.provenance);
+}