fix(ui): route external links out of the Android VK WebView

The Android VK client's WebView ignores target=_blank and navigates the
Mini App's own window to the target, stranding the player outside the
game with no way back (the dictionary lookup, About/Feedback links, the
ad banner and the bot-link modal fallbacks). vk-bridge 3.x has no method
to open an external URL, so external links are routed through VK's own
leave-VK redirect (vk.com/away.php), which the client intercepts
natively and hands to the system browser.

onExternalLinkClick moves from lib/telegram to a new lib/links that
composes the Telegram and VK routers; iOS and desktop VK open _blank
correctly and are left alone.

ui/src/lib/links.ts

@@ -0,0 +1,31 @@
+// Platform-aware external-link opening. Both Mini App hosts mishandle a plain target=_blank
+// anchor: Telegram shows the WebView's generic "open this link?" confirmation, and the Android VK
+// client navigates the app's own WebView to the target with no way back to the game. The helpers
+// below route an external URL through the platform's escape hatch (Telegram's openLink, VK's
+// away.php redirect) and leave the anchor's own navigation / window.open in effect elsewhere.
+
+import { routeExternalLinkInTelegram } from './telegram';
+import { routeExternalLinkInVK, vkOpenExternalUrl } from './vk';
+
+/**
+ * onExternalLinkClick is the anchor click handler for external links. It resolves the clicked
+ * anchor with closest(), so it works both attached directly on an <a> and delegated on a container
+ * that renders links (e.g. {@html} markdown). Attach it as onclick on an external link or its
+ * container; outside Telegram and VK it is a no-op and the anchor's own target=_blank handles the
+ * click.
+ */
+export function onExternalLinkClick(e: MouseEvent): void {
+  const a = (e.target as HTMLElement | null)?.closest('a');
+  if (!a) return;
+  if (routeExternalLinkInTelegram(a) || routeExternalLinkInVK(a)) e.preventDefault();
+}
+
+/**
+ * openExternalUrl opens an external URL from code (no anchor to click): through VK's external
+ * redirect inside the Android VK client, else a plain new tab. Telegram callers try their native
+ * opener (telegramOpenLink) first and use this as the fallback.
+ */
+export function openExternalUrl(url: string): void {
+  if (vkOpenExternalUrl(url)) return;
+  if (typeof window !== 'undefined') window.open(url, '_blank');
+}