fix(telegram): refresh global undici dispatcher for autoSelectFamily (#25682)

Land PR #25682 from @lairtonlelis after maintainer rework:
track dispatcher updates when network decision changes to avoid stale global fetch behavior.

Co-authored-by: Ailton <lairton@telnyx.com>

src/telegram/fetch.ts

@@ -1,5 +1,6 @@
 import * as dns from "node:dns";
 import * as net from "node:net";
+import { Agent, setGlobalDispatcher } from "undici";
 import type { TelegramNetworkConfig } from "../config/types.telegram.js";
 import { resolveFetch } from "../infra/fetch.js";
 import { createSubsystemLogger } from "../logging/subsystem.js";
@@ -10,6 +11,7 @@ import {
 
 let appliedAutoSelectFamily: boolean | null = null;
 let appliedDnsResultOrder: string | null = null;
+let appliedGlobalDispatcherAutoSelectFamily: boolean | null = null;
 const log = createSubsystemLogger("telegram/network");
 
 // Node 22 workaround: enable autoSelectFamily to allow IPv4 fallback on broken IPv6 networks.
@@ -31,6 +33,33 @@ function applyTelegramNetworkWorkarounds(network?: TelegramNetworkConfig): void
     }
   }
 
+  // Node 22's built-in globalThis.fetch uses undici's internal Agent whose
+  // connect options are frozen at construction time. Calling
+  // net.setDefaultAutoSelectFamily() after that agent is created has no
+  // effect on it. Replace the global dispatcher with one that carries the
+  // current autoSelectFamily setting so subsequent globalThis.fetch calls
+  // inherit the same decision.
+  // See: https://github.com/openclaw/openclaw/issues/25676
+  if (
+    autoSelectDecision.value !== null &&
+    autoSelectDecision.value !== appliedGlobalDispatcherAutoSelectFamily
+  ) {
+    try {
+      setGlobalDispatcher(
+        new Agent({
+          connect: {
+            autoSelectFamily: autoSelectDecision.value,
+            autoSelectFamilyAttemptTimeout: 300,
+          },
+        }),
+      );
+      appliedGlobalDispatcherAutoSelectFamily = autoSelectDecision.value;
+      log.info(`global undici dispatcher autoSelectFamily=${autoSelectDecision.value}`);
+    } catch {
+      // ignore if setGlobalDispatcher is unavailable
+    }
+  }
+
   // Apply DNS result order workaround for IPv4/IPv6 issues.
   // Some APIs (including Telegram) may fail with IPv6 on certain networks.
   // See: https://github.com/openclaw/openclaw/issues/5311
@@ -68,4 +97,5 @@ export function resolveTelegramFetch(
 export function resetTelegramFetchStateForTests(): void {
   appliedAutoSelectFamily = null;
   appliedDnsResultOrder = null;
+  appliedGlobalDispatcherAutoSelectFamily = null;
 }