Telegram: harden network retries and config

Co-authored-by: techboss <techboss@users.noreply.github.com>

src/telegram/fetch.ts

@@ -1,19 +1,36 @@
-import { setDefaultAutoSelectFamily } from "net";
+import * as net from "node:net";
 import { resolveFetch } from "../infra/fetch.js";
+import type { TelegramNetworkConfig } from "../config/types.telegram.js";
+import { createSubsystemLogger } from "../logging/subsystem.js";
+import { resolveTelegramAutoSelectFamilyDecision } from "./network-config.js";
 
-// Workaround for Node.js 22 "Happy Eyeballs" (autoSelectFamily) bug
-// that causes intermittent ETIMEDOUT errors when connecting to Telegram's
-// dual-stack servers. Disabling autoSelectFamily forces sequential IPv4/IPv6
-// attempts which works reliably.
+let appliedAutoSelectFamily: boolean | null = null;
+const log = createSubsystemLogger("telegram/network");
+
+// Node 22 workaround: disable autoSelectFamily to avoid Happy Eyeballs timeouts.
 // See: https://github.com/nodejs/node/issues/54359
-try {
-  setDefaultAutoSelectFamily(false);
-} catch {
-  // Ignore if not available (older Node versions)
+function applyTelegramNetworkWorkarounds(network?: TelegramNetworkConfig): void {
+  const decision = resolveTelegramAutoSelectFamilyDecision({ network });
+  if (decision.value === null || decision.value === appliedAutoSelectFamily) return;
+  appliedAutoSelectFamily = decision.value;
+
+  if (typeof net.setDefaultAutoSelectFamily === "function") {
+    try {
+      net.setDefaultAutoSelectFamily(decision.value);
+      const label = decision.source ? ` (${decision.source})` : "";
+      log.info(`telegram: autoSelectFamily=${decision.value}${label}`);
+    } catch {
+      // ignore if unsupported by the runtime
+    }
+  }
 }
 
 // Prefer wrapped fetch when available to normalize AbortSignal across runtimes.
-export function resolveTelegramFetch(proxyFetch?: typeof fetch): typeof fetch | undefined {
+export function resolveTelegramFetch(
+  proxyFetch?: typeof fetch,
+  options?: { network?: TelegramNetworkConfig },
+): typeof fetch | undefined {
+  applyTelegramNetworkWorkarounds(options?.network);
   if (proxyFetch) return resolveFetch(proxyFetch);
   const fetchImpl = resolveFetch();
   if (!fetchImpl) {