fix: strip envelopes in chat history

src/gateway/chat-sanitize.ts

@@ -0,0 +1,89 @@
+const ENVELOPE_PREFIX = /^\[([^\]]+)\]\s*/;
+const ENVELOPE_CHANNELS = [
+  "WebChat",
+  "WhatsApp",
+  "Telegram",
+  "Signal",
+  "Slack",
+  "Discord",
+  "iMessage",
+  "Teams",
+  "Matrix",
+  "Zalo",
+  "Zalo Personal",
+  "BlueBubbles",
+];
+
+function looksLikeEnvelopeHeader(header: string): boolean {
+  if (/\d{4}-\d{2}-\d{2}T\d{2}:\d{2}Z\b/.test(header)) return true;
+  if (/\d{4}-\d{2}-\d{2} \d{2}:\d{2}\b/.test(header)) return true;
+  return ENVELOPE_CHANNELS.some((label) => header.startsWith(`${label} `));
+}
+
+export function stripEnvelope(text: string): string {
+  const match = text.match(ENVELOPE_PREFIX);
+  if (!match) return text;
+  const header = match[1] ?? "";
+  if (!looksLikeEnvelopeHeader(header)) return text;
+  return text.slice(match[0].length);
+}
+
+function stripEnvelopeFromContent(content: unknown[]): { content: unknown[]; changed: boolean } {
+  let changed = false;
+  const next = content.map((item) => {
+    if (!item || typeof item !== "object") return item;
+    const entry = item as Record<string, unknown>;
+    if (entry.type !== "text" || typeof entry.text !== "string") return item;
+    const stripped = stripEnvelope(entry.text);
+    if (stripped === entry.text) return item;
+    changed = true;
+    return {
+      ...entry,
+      text: stripped,
+    };
+  });
+  return { content: next, changed };
+}
+
+export function stripEnvelopeFromMessage(message: unknown): unknown {
+  if (!message || typeof message !== "object") return message;
+  const entry = message as Record<string, unknown>;
+  const role = typeof entry.role === "string" ? entry.role.toLowerCase() : "";
+  if (role !== "user") return message;
+
+  let changed = false;
+  const next: Record<string, unknown> = { ...entry };
+
+  if (typeof entry.content === "string") {
+    const stripped = stripEnvelope(entry.content);
+    if (stripped !== entry.content) {
+      next.content = stripped;
+      changed = true;
+    }
+  } else if (Array.isArray(entry.content)) {
+    const updated = stripEnvelopeFromContent(entry.content);
+    if (updated.changed) {
+      next.content = updated.content;
+      changed = true;
+    }
+  } else if (typeof entry.text === "string") {
+    const stripped = stripEnvelope(entry.text);
+    if (stripped !== entry.text) {
+      next.text = stripped;
+      changed = true;
+    }
+  }
+
+  return changed ? next : message;
+}
+
+export function stripEnvelopeFromMessages(messages: unknown[]): unknown[] {
+  if (messages.length === 0) return messages;
+  let changed = false;
+  const next = messages.map((message) => {
+    const stripped = stripEnvelopeFromMessage(message);
+    if (stripped !== message) changed = true;
+    return stripped;
+  });
+  return changed ? next : messages;
+}