fix(whatsapp): normalize user JIDs for group allowlists (#838)

Thanks @peschee.

Co-authored-by: Peter Siska <63866+peschee@users.noreply.github.com>

src/whatsapp/normalize.ts

@@ -1,5 +1,8 @@
 import { normalizeE164 } from "../utils.js";
 
+const WHATSAPP_USER_JID_RE = /^(\d+)(?::\d+)?@s\.whatsapp\.net$/i;
+const WHATSAPP_LID_RE = /^(\d+)@lid$/i;
+
 function stripWhatsAppTargetPrefixes(value: string): string {
   let candidate = value.trim();
   for (;;) {
@@ -21,6 +24,27 @@ export function isWhatsAppGroupJid(value: string): boolean {
   return /^[0-9]+(-[0-9]+)*$/.test(localPart);
 }
 
+/**
+ * Check if value looks like a WhatsApp user JID (e.g. "41796666864:0@s.whatsapp.net" or "123@lid").
+ */
+export function isWhatsAppUserJid(value: string): boolean {
+  const candidate = stripWhatsAppTargetPrefixes(value);
+  return WHATSAPP_USER_JID_RE.test(candidate) || WHATSAPP_LID_RE.test(candidate);
+}
+
+/**
+ * Extract the phone number from a WhatsApp user JID.
+ * "41796666864:0@s.whatsapp.net" -> "41796666864"
+ * "123456@lid" -> "123456"
+ */
+function extractUserJidPhone(jid: string): string | null {
+  const userMatch = jid.match(WHATSAPP_USER_JID_RE);
+  if (userMatch) return userMatch[1];
+  const lidMatch = jid.match(WHATSAPP_LID_RE);
+  if (lidMatch) return lidMatch[1];
+  return null;
+}
+
 export function normalizeWhatsAppTarget(value: string): string | null {
   const candidate = stripWhatsAppTargetPrefixes(value);
   if (!candidate) return null;
@@ -28,6 +52,13 @@ export function normalizeWhatsAppTarget(value: string): string | null {
     const localPart = candidate.slice(0, candidate.length - "@g.us".length);
     return `${localPart}@g.us`;
   }
+  // Handle user JIDs (e.g. "41796666864:0@s.whatsapp.net")
+  if (isWhatsAppUserJid(candidate)) {
+    const phone = extractUserJidPhone(candidate);
+    if (!phone) return null;
+    const normalized = normalizeE164(phone);
+    return normalized.length > 1 ? normalized : null;
+  }
   const normalized = normalizeE164(candidate);
   return normalized.length > 1 ? normalized : null;
 }