docs(marketing): Update GPS feature description in beta flyer

Revised the GPS feature description from "GPS-Tracks" to "GPS-Track Upload" for improved clarity. Updated the corresponding PDF to reflect this change.

docs/marketing/beta-flyer.html

@@ -251,7 +251,7 @@
       <div class="feature"><span class="feature-icon">✦</span><span>Reisetage im nautischen Logbuch-Format (Hafen, Wetter, Besegelung, Crew, Tankstände, etc.)</span></div>
       <div class="feature"><span class="feature-icon">✦</span><span>Offline-fähige PWA — läuft auf jedem Smartphone &amp; Tablet</span></div>
       <div class="feature"><span class="feature-icon">✦</span><span>Passkey-Anmeldung &amp; Ende-zu-Ende Verschlüsselung</span></div>
-      <div class="feature"><span class="feature-icon">✦</span><span>GPS-Tracks (GPX/KML), Karte &amp; Streckenstatistik</span></div>
+      <div class="feature"><span class="feature-icon">✦</span><span>GPS-Track Upload (GPX/KML), Karte &amp; Streckenstatistik</span></div>
       <div class="feature"><span class="feature-icon">✦</span><span>Foto-Anhänge pro Reisetag</span></div>
       <div class="feature"><span class="feature-icon">✦</span><span>Crew einladen — gemeinsam am Logbuch arbeiten</span></div>
       <div class="feature"><span class="feature-icon">✦</span><span>PDF- &amp; CSV-Export</span></div>