Feature: Ratings, Lightbox, Forum-Standort, Notifications, Routen-Recording, Chat-Picker

- Bewertungssystem (ratings.py): Sterne für Sitter/Walks/Places/Routen
- Admin: Server-Log-Viewer + OSM-Cache-Statistiken
- Chat: "Neue Nachricht"-Button mit Freundesliste-Picker
- Forum: 5 neue Kategorien, Standorteingabe (locationPicker), Absende-Toast, Lightbox
- Freunde: Aktivitäts-Filter (Chips), Freundschaftsanfrage → In-App-Notification
- Sitter: locationPicker statt manuelle Koordinateneingabe + ratingStars
- Tagebuch: Bilder-Lightbox im Detail-View, iOS-Modal-Header-Fix (90svh)
- Routen: Start/Stopp-Button wechselt Zustand, nutzt Page_map.isRecording()
- Benachrichtigungen: Delete-Button sichtbar, typ-basierte Navigation, Toast-Feedback
- OSM: globales Semaphore + 429-Retry-Logic; Scheduler: München-Umland, täglich
- SW by-v225, APP_VER 202

backend/static/js/pages/friends.js

@@ -196,36 +196,56 @@ window.Page_friends = (() => {
     }
   }
 
+  let _activityFilter = 'alle';
+  let _activityAll    = [];
+
   function _renderActivity(items) {
+    _activityAll = items;
     const el = _container.querySelector('#fr-activity');
     if (!el) return;
 
-    if (!items.length) {
-      el.innerHTML = `
-        <div style="margin-top:var(--space-6)">
-          <div class="by-section-label">Aktivitäten</div>
-          <div style="text-align:center;padding:var(--space-8) var(--space-4)">
-            <svg class="ph-icon" style="width:40px;height:40px;color:var(--c-border);
-                 margin-bottom:var(--space-3)" aria-hidden="true">
-              <use href="/icons/phosphor.svg#paw-print"></use>
-            </svg>
-            <p style="font-size:var(--text-sm);color:var(--c-text-secondary);margin:0">
-              Noch keine Aktivitäten. Füge Freunde hinzu!
-            </p>
-          </div>
-        </div>
-      `;
-      return;
-    }
+    const FILTERS = [
+      { key: 'alle',     label: 'Alle' },
+      { key: 'diary',    label: 'Tagebuch' },
+      { key: 'walk',     label: 'Gassi-Treffen' },
+      { key: 'health',   label: 'Gesundheit' },
+      { key: 'new_dog',  label: 'Neuer Hund' },
+    ];
+
+    const chips = FILTERS.map(f => `
+      <button class="rk-chip${_activityFilter === f.key ? ' active' : ''}"
+              data-af="${f.key}">${f.label}</button>
+    `).join('');
+
+    const filtered = _activityFilter === 'alle'
+      ? items
+      : items.filter(i => i.type === _activityFilter);
 
     el.innerHTML = `
       <div style="margin-top:var(--space-6)">
         <div class="by-section-label">Aktivitäten</div>
-        <div class="fr-activity-timeline">
-          ${items.map(item => _activityItem(item)).join('')}
+        <div class="rk-filter-group" style="margin-bottom:var(--space-3);flex-wrap:wrap">
+          ${chips}
         </div>
+        ${!filtered.length
+          ? `<div style="text-align:center;padding:var(--space-8) var(--space-4)">
+               <p style="font-size:var(--text-sm);color:var(--c-text-secondary);margin:0">
+                 Keine Einträge in dieser Kategorie.
+               </p>
+             </div>`
+          : `<div class="fr-activity-timeline">
+               ${filtered.map(item => _activityItem(item)).join('')}
+             </div>`
+        }
       </div>
     `;
+
+    el.querySelectorAll('[data-af]').forEach(btn => {
+      btn.addEventListener('click', () => {
+        _activityFilter = btn.dataset.af;
+        _renderActivity(_activityAll);
+      });
+    });
   }
 
   function _activityItem(item) {