move anchor config to frontend dropdowns + localStorage, remove /api/settings

wwwroot/index.html

@@ -10,6 +10,15 @@
   <header>
     <h1>Cost Analytics</h1>
     <div id="summary"></div>
+    <div id="anchor-config">
+      <label>Anker:</label>
+      <select id="anchor-day">
+        <option value="0">So</option><option value="1">Mo</option><option value="2">Di</option>
+        <option value="3">Mi</option><option value="4">Do</option><option value="5">Fr</option>
+        <option value="6">Sa</option>
+      </select>
+      <select id="anchor-hour"></select>
+    </div>
     <button id="btn-sync" title="Neue Einträge importieren">↻ Sync</button>
   </header>