feat(tender-radar): add settings gear link on module page

The tender-radar settings page (with the E-Mail-Alerts form) was only
reachable by manually typing the literal URL /modules/tender-radar/settings
— no on-screen link existed, and appending /settings to the dynamic
[category]/[moduleSlug] URL returns 'Modul nicht gefunden'. Add a gear-icon
Link (mirroring dkv-fleet's pattern) pointing at the literal settings route,
plus a tenderRadar.page.settingsTitle key in de/en.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/web/src/app/(portal)/modules/tender-radar/page.tsx

@@ -3,6 +3,7 @@
 import { Suspense } from 'react';
 import { useTranslations } from 'next-intl';
 import { useRouter, useSearchParams } from 'next/navigation';
+import Link from 'next/link';
 import { CoverageBanner } from './components/CoverageBanner';
 import { FilterPanel } from './components/FilterPanel';
 import { ResultsList } from './components/ResultsList';
@@ -52,10 +53,29 @@ function TenderRadarContent() {
 
   return (
     <div className="mx-auto max-w-5xl space-y-6 p-6">
-      <div>
+      <div className="flex items-start justify-between gap-4">
         <h1 className="text-2xl font-bold tracking-tight">
           {t('page.title')}
         </h1>
+
+        {/*
+         * Einstellungen-Link. Absolute literal href (NOT the dynamic
+         * [category]/[moduleSlug] basePath): the tender-radar settings page
+         * only exists as the literal route /modules/tender-radar/settings —
+         * the dynamic settings route returns "Modul nicht gefunden" for this
+         * module, so the gear must point at the literal path directly.
+         */}
+        <Link
+          href="/modules/tender-radar/settings"
+          className="rounded border border-border px-3 py-2 text-sm text-muted-foreground transition-colors hover:bg-muted hover:text-foreground"
+          title={t('page.settingsTitle')}
+          aria-label={t('page.settingsTitle')}
+        >
+          <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round" aria-hidden="true">
+            <circle cx="12" cy="12" r="3" />
+            <path d="M19.4 15a1.65 1.65 0 0 0 .33 1.82l.06.06a2 2 0 0 1-2.83 2.83l-.06-.06a1.65 1.65 0 0 0-1.82-.33 1.65 1.65 0 0 0-1 1.51V21a2 2 0 0 1-4 0v-.09A1.65 1.65 0 0 0 9 19.4a1.65 1.65 0 0 0-1.82.33l-.06.06a2 2 0 0 1-2.83-2.83l.06-.06A1.65 1.65 0 0 0 4.68 15a1.65 1.65 0 0 0-1.51-1H3a2 2 0 0 1 0-4h.09A1.65 1.65 0 0 0 4.6 9a1.65 1.65 0 0 0-.33-1.82l-.06-.06a2 2 0 0 1 2.83-2.83l.06.06A1.65 1.65 0 0 0 9 4.68a1.65 1.65 0 0 0 1-1.51V3a2 2 0 0 1 4 0v.09a1.65 1.65 0 0 0 1 1.51 1.65 1.65 0 0 0 1.82-.33l.06-.06a2 2 0 0 1 2.83 2.83l-.06.06A1.65 1.65 0 0 0 19.4 9a1.65 1.65 0 0 0 1.51 1H21a2 2 0 0 1 0 4h-.09a1.65 1.65 0 0 0-1.51 1z" />
+          </svg>
+        </Link>
       </div>
 
       <CoverageBanner />