fix(session): ignore internal synthetic turns

src/shared/internal-initiator-marker.ts

@@ -1,7 +1,66 @@
 export const OMO_INTERNAL_INITIATOR_MARKER = "<!-- OMO_INTERNAL_INITIATOR -->"
 
+const INTERNAL_INITIATOR_MARKER_DETECT_PATTERN = /<!--\s*OMO_INTERNAL_INITIATOR\s*-->/
 const INTERNAL_INITIATOR_MARKER_PATTERN = /\n*<!--\s*OMO_INTERNAL_INITIATOR\s*-->\s*/g
 
+export type InternalInitiatorTextPartLike = {
+  type?: string
+  text?: string
+  synthetic?: boolean
+}
+
+export type InternalInitiatorMessageLike = {
+  role?: string
+  info?: { role?: string }
+  parts?: readonly InternalInitiatorTextPartLike[]
+}
+
+export function hasInternalInitiatorMarker(text: string): boolean {
+  return INTERNAL_INITIATOR_MARKER_DETECT_PATTERN.test(text)
+}
+
+export function isTextPartLike(
+  part: InternalInitiatorTextPartLike
+): part is InternalInitiatorTextPartLike & { type: "text"; text: string } {
+  return part.type === "text" && typeof part.text === "string"
+}
+
+export function isSyntheticOrInternalTextPart(
+  part: InternalInitiatorTextPartLike
+): boolean {
+  return (
+    isTextPartLike(part) &&
+    (part.synthetic === true || hasInternalInitiatorMarker(part.text))
+  )
+}
+
+export function isRealUserTextPart(
+  part: InternalInitiatorTextPartLike
+): part is InternalInitiatorTextPartLike & { type: "text"; text: string } {
+  return isTextPartLike(part) && !isSyntheticOrInternalTextPart(part)
+}
+
+export function isSyntheticOrInternalOnlyTextParts(
+  parts: readonly InternalInitiatorTextPartLike[] | undefined
+): boolean {
+  const textParts = (parts ?? []).filter(isTextPartLike)
+  return textParts.length > 0 && textParts.every(isSyntheticOrInternalTextPart)
+}
+
+export function isSyntheticOrInternalUserMessage(
+  message: InternalInitiatorMessageLike
+): boolean {
+  const role = message.info?.role ?? message.role
+  return role === "user" && isSyntheticOrInternalOnlyTextParts(message.parts)
+}
+
+export function isRealUserMessage(
+  message: InternalInitiatorMessageLike
+): boolean {
+  const role = message.info?.role ?? message.role
+  return role === "user" && !isSyntheticOrInternalUserMessage(message)
+}
+
 export function stripInternalInitiatorMarkers(text: string): string {
   return text.replace(INTERNAL_INITIATOR_MARKER_PATTERN, "").trimEnd()
 }