fix: persist resolved telegram delivery targets at runtime

src/telegram/targets.ts

@@ -4,6 +4,9 @@ export type TelegramTarget = {
   chatType: "direct" | "group" | "unknown";
 };
 
+const TELEGRAM_NUMERIC_CHAT_ID_REGEX = /^-?\d+$/;
+const TELEGRAM_USERNAME_REGEX = /^[A-Za-z0-9_]{5,}$/i;
+
 export function stripTelegramInternalPrefixes(to: string): string {
   let trimmed = to.trim();
   let strippedTelegramPrefix = false;
@@ -26,6 +29,46 @@ export function stripTelegramInternalPrefixes(to: string): string {
   }
 }
 
+export function normalizeTelegramChatId(raw: string): string | undefined {
+  const stripped = stripTelegramInternalPrefixes(raw);
+  if (!stripped) {
+    return undefined;
+  }
+  if (TELEGRAM_NUMERIC_CHAT_ID_REGEX.test(stripped)) {
+    return stripped;
+  }
+  return undefined;
+}
+
+export function isNumericTelegramChatId(raw: string): boolean {
+  return TELEGRAM_NUMERIC_CHAT_ID_REGEX.test(raw.trim());
+}
+
+export function normalizeTelegramLookupTarget(raw: string): string | undefined {
+  const stripped = stripTelegramInternalPrefixes(raw);
+  if (!stripped) {
+    return undefined;
+  }
+  if (isNumericTelegramChatId(stripped)) {
+    return stripped;
+  }
+  const tmeMatch = /^(?:https?:\/\/)?t\.me\/([A-Za-z0-9_]+)$/i.exec(stripped);
+  if (tmeMatch?.[1]) {
+    return `@${tmeMatch[1]}`;
+  }
+  if (stripped.startsWith("@")) {
+    const handle = stripped.slice(1);
+    if (!handle || !TELEGRAM_USERNAME_REGEX.test(handle)) {
+      return undefined;
+    }
+    return `@${handle}`;
+  }
+  if (TELEGRAM_USERNAME_REGEX.test(stripped)) {
+    return `@${stripped}`;
+  }
+  return undefined;
+}
+
 /**
  * Parse a Telegram delivery target into chatId and optional topic/thread ID.
  *
@@ -39,7 +82,7 @@ function resolveTelegramChatType(chatId: string): "direct" | "group" | "unknown"
   if (!trimmed) {
     return "unknown";
   }
-  if (/^-?\d+$/.test(trimmed)) {
+  if (isNumericTelegramChatId(trimmed)) {
     return trimmed.startsWith("-") ? "group" : "direct";
   }
   return "unknown";