feat(ui): route all in-app external links through Telegram openLink

Extend the openLink routing from the dictionary lookup to every external
link shown inside the Mini App, so none triggers the WebView's 'open this
link?' confirmation. A shared onExternalLinkClick handler resolves the anchor
via closest() (so it also works delegated on {@html} content), backed by a
pure routeExternalLinkInTelegram decision: only inside Telegram, only an
external http(s) target=_blank link, excluding same-origin/in-app and t.me
links (t.me keeps openTelegramLink). Applied to the word-check lookup, the
About rules link, the Feedback operator-reply links, and the feature-gated
announcement banner.

Outside Telegram every anchor keeps its native target=_blank.

ui/src/lib/telegram.test.ts

@@ -1,6 +1,7 @@
 import { afterEach, describe, expect, it, vi } from 'vitest';
 import {
   insideTelegram,
+  routeExternalLinkInTelegram,
   telegramClosingConfirmation,
   telegramLaunch,
   telegramOpenExternalLink,
@@ -121,3 +122,36 @@ describe('telegramOpenExternalLink', () => {
     expect(telegramOpenExternalLink('https://x.io')).toBe(false);
   });
 });
+
+describe('routeExternalLinkInTelegram', () => {
+  afterEach(() => vi.unstubAllGlobals());
+
+  function stubInside(openLink = vi.fn(), origin = 'https://app.example') {
+    vi.stubGlobal('window', { Telegram: { WebApp: { initData: 'query_id=abc', openLink } } });
+    vi.stubGlobal('location', { href: origin + '/', origin });
+    return openLink;
+  }
+
+  it('routes an external http(s) _blank link through openLink inside Telegram', () => {
+    const openLink = stubInside();
+    expect(routeExternalLinkInTelegram({ href: 'https://gramota.ru/poisk?query=кот', target: '_blank' })).toBe(true);
+    expect(openLink).toHaveBeenCalledWith('https://gramota.ru/poisk?query=кот');
+  });
+
+  it('leaves a t.me link to the native handler (openTelegramLink owns those)', () => {
+    const openLink = stubInside();
+    expect(routeExternalLinkInTelegram({ href: 'https://t.me/some_bot', target: '_blank' })).toBe(false);
+    expect(openLink).not.toHaveBeenCalled();
+  });
+
+  it('leaves same-origin and non-_blank links to in-app navigation', () => {
+    const openLink = stubInside(vi.fn(), 'https://app.example');
+    expect(routeExternalLinkInTelegram({ href: 'https://app.example/lobby', target: '_blank' })).toBe(false);
+    expect(routeExternalLinkInTelegram({ href: 'https://gramota.ru', target: '' })).toBe(false);
+    expect(openLink).not.toHaveBeenCalled();
+  });
+
+  it('does nothing outside Telegram (the anchor opens natively)', () => {
+    expect(routeExternalLinkInTelegram({ href: 'https://x.io', target: '_blank' })).toBe(false);
+  });
+});