fix: Notification opens ComposeMainActivity, WiFi-Only toggle in own section

Fixes:
1. Notification click now opens ComposeMainActivity instead of legacy MainActivity
2. WiFi-Only toggle moved to its own 'Network Restriction' section at top of sync settings
3. Added hint explaining WiFi-Connect trigger is not affected by WiFi-Only setting

UI Changes:
- New section header: 'Network Restriction' / 'Netzwerk-Einschränkung'
- WiFi-Only toggle now clearly separated from sync triggers
- Info card shows when WiFi-Only is enabled explaining the exception

android/app/src/main/res/values-de/strings.xml

@@ -206,10 +206,13 @@
     <string name="auto_sync_info">ℹ️ Auto-Sync:\n\n• Prüft alle 30 Min ob Server erreichbar\n• Funktioniert bei jeder WiFi-Verbindung\n• Läuft auch im Hintergrund\n• Minimaler Akkuverbrauch (~0.4%%/Tag)</string>
     
     <!-- 🌟 v1.6.0: Configurable Sync Triggers -->
+    <string name="sync_section_network">📶 Netzwerk-Einschränkung</string>
     <string name="sync_section_instant">📲 Sofort-Sync</string>
     <string name="sync_section_background">📡 Hintergrund-Sync</string>
     <string name="sync_section_advanced">⚙️ Erweitert</string>
     
+    <string name="sync_wifi_only_hint">💡 Der WiFi-Connect Trigger ist davon nicht betroffen \u2013 er synchronisiert immer wenn WiFi verbunden wird.</string>
+    
     <string name="sync_trigger_on_save_title">Nach dem Speichern</string>
     <string name="sync_trigger_on_save_subtitle">Sync sofort nach jeder Änderung</string>
     
@@ -228,7 +231,7 @@
     <!-- 🆕 v1.7.0: WiFi-Only Sync -->
     <string name="sync_wifi_only_title">Sync nur im WLAN</string>
     <string name="sync_wifi_only_subtitle">Sync wird nur durchgeführt wenn WLAN verbunden ist. Spart mobiles Datenvolumen und verhindert lange Wartezeit.</string>
-    <string name="sync_wifi_only_hint">Sync nur im WLAN möglich</string>
+    <string name="sync_wifi_only_blocked">Sync nur im WLAN möglich</string>
     
     <string name="sync_manual_hint">Manueller Sync (Toolbar/Pull-to-Refresh) ist ebenfalls verfügbar.</string>
     <string name="sync_manual_hint_disabled">Sync ist im Offline-Modus nicht verfügbar.</string>

android/app/src/main/res/values/strings.xml

@@ -206,10 +206,13 @@
     <string name="auto_sync_info">ℹ️ Auto-Sync:\n\n• Checks every 30 min if server is reachable\n• Works on any WiFi connection\n• Runs in background\n• Minimal battery usage (~0.4%%/day)</string>
     
     <!-- 🌟 v1.6.0: Configurable Sync Triggers -->
+    <string name="sync_section_network">📶 Network Restriction</string>
     <string name="sync_section_instant">📲 Instant Sync</string>
     <string name="sync_section_background">📡 Background Sync</string>
     <string name="sync_section_advanced">⚙️ Advanced</string>
     
+    <string name="sync_wifi_only_hint">💡 WiFi-Connect Trigger is not affected by this setting \u2013 it always syncs when WiFi is connected.</string>
+    
     <string name="sync_trigger_on_save_title">After Saving</string>
     <string name="sync_trigger_on_save_subtitle">Sync immediately after each change</string>
     
@@ -228,7 +231,7 @@
     <!-- 🆕 v1.7.0: WiFi-Only Sync -->
     <string name="sync_wifi_only_title">WiFi-only sync</string>
     <string name="sync_wifi_only_subtitle">Sync only when connected to WiFi. Saves mobile data and prevents long wait times.</string>
-    <string name="sync_wifi_only_hint">Sync only works when connected to WiFi</string>
+    <string name="sync_wifi_only_blocked">Sync only works when connected to WiFi</string>
     
     <string name="sync_manual_hint">Manual sync (toolbar/pull-to-refresh) is also available.</string>
     <string name="sync_manual_hint_disabled">Sync is not available in offline mode.</string>