feat(Networking): enhance offline handling and localization for diary and members data

- Added `ACCESS_NETWORK_STATE` permission in AndroidManifest.xml to monitor network connectivity.
- Introduced `NetworkConnectivityHolder` to manage network state and trigger data refresh when connectivity is restored.
- Updated `DiaryManager` and `MembersManager` to support offline caching, allowing users to view previously loaded data when offline.
- Enhanced localization by adding new keys for offline cache hints in both German and English, improving user experience during connectivity issues.
- Updated UI components to display offline cache messages, ensuring users are informed when data is being served from cache.

mobile-app/composeApp/build.gradle.kts

@@ -58,8 +58,8 @@ android {
         applicationId = "de.tsschulz.tt_tagebuch"
         minSdk = libs.versions.android.minSdk.get().toInt()
         targetSdk = libs.versions.android.targetSdk.get().toInt()
-        versionCode = 4
-        versionName = "1.2.0"
+        versionCode = libs.versions.appVersionCode.get().toInt()
+        versionName = libs.versions.appVersionName.get()
         buildConfigField("String", "BACKEND_BASE_URL", "\"$backendBaseUrl\"")
         buildConfigField("String", "SOCKET_BASE_URL", "\"$socketBaseUrl\"")
     }

mobile-app/composeApp/src/androidMain/AndroidManifest.xml

@@ -2,6 +2,7 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
 
     <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
 
     <application
         android:name=".app.MainApplication"

mobile-app/composeApp/src/androidMain/kotlin/de/tsschulz/tt_tagebuch/app/AppDependencies.kt

@@ -2,6 +2,7 @@ package de.tsschulz.tt_tagebuch.app
 
 import android.content.Context
 import de.tsschulz.tt_tagebuch.BuildConfig
+import de.tsschulz.tt_tagebuch.app.net.NetworkConnectivityHolder
 import de.tsschulz.tt_tagebuch.shared.api.BillingApi
 import de.tsschulz.tt_tagebuch.shared.api.CalendarHolidayApi
 import de.tsschulz.tt_tagebuch.shared.api.AccidentApi
@@ -68,6 +69,7 @@ class AppDependencies(context: Context) {
      * (z. B. Club wählen → anderer Screen), im Gegensatz zu [rememberCoroutineScope].
      */
     val applicationScope = CoroutineScope(applicationJob + Dispatchers.Main.immediate)
+    val networkConnectivity = NetworkConnectivityHolder(context.applicationContext)
     val apiConfig = ApiConfig(baseUrl = BuildConfig.BACKEND_BASE_URL)
     val unauthorizedEvents = MutableStateFlow(0)
     private val tokenProvider = MutableTokenProvider()

mobile-app/composeApp/src/androidMain/kotlin/de/tsschulz/tt_tagebuch/app/net/NetworkConnectivityHolder.kt

@@ -0,0 +1,44 @@
+package de.tsschulz.tt_tagebuch.app.net
+
+import android.content.Context
+import android.net.ConnectivityManager
+import android.net.Network
+import android.net.NetworkCapabilities
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+
+/**
+ * Beobachtet die Standard-Netzwerkverbindung (z. B. für Reconnect-Refresh von Tagebuch/Mitgliedern).
+ */
+class NetworkConnectivityHolder(context: Context) {
+    private val appContext = context.applicationContext
+    private val cm = appContext.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
+    private val _connected = MutableStateFlow(readConnected())
+    val connected: StateFlow<Boolean> = _connected.asStateFlow()
+
+    private val callback = object : ConnectivityManager.NetworkCallback() {
+        override fun onCapabilitiesChanged(network: Network, networkCapabilities: NetworkCapabilities) {
+            _connected.value = networkCapabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
+        }
+
+        override fun onLost(network: Network) {
+            _connected.value = readConnected()
+        }
+
+        override fun onAvailable(network: Network) {
+            _connected.value = readConnected()
+        }
+    }
+
+    init {
+        cm.registerDefaultNetworkCallback(callback)
+        _connected.value = readConnected()
+    }
+
+    private fun readConnected(): Boolean {
+        val network = cm.activeNetwork ?: return false
+        val caps = cm.getNetworkCapabilities(network) ?: return false
+        return caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
+    }
+}

mobile-app/composeApp/src/androidMain/kotlin/de/tsschulz/tt_tagebuch/app/ui/AppRoot.kt

@@ -257,6 +257,40 @@ private fun MainTabs(dependencies: AppDependencies) {
     val useWideMainNav = LocalConfiguration.current.screenWidthDp >= MAIN_NAV_RAIL_MIN_WIDTH_DP
     val clubState by dependencies.clubManager.state.collectAsState()
     val visibleTabs = visibleMainTabs(clubState.currentPermissions)
+    val networkConnected by dependencies.networkConnectivity.connected.collectAsState()
+    var lastNetworkConnected by remember { mutableStateOf(true) }
+
+    /** Tagebuch- und Mitglieder-Listen vorladen, sobald Verein + Rechte feststehen. */
+    LaunchedEffect(clubState.currentClubId, clubState.currentPermissions) {
+        val id = clubState.currentClubId ?: return@LaunchedEffect
+        val perms = clubState.currentPermissions ?: return@LaunchedEffect
+        dependencies.applicationScope.launch {
+            if (perms.canReadDiary()) {
+                dependencies.diaryManager.loadDates(id)
+            }
+            if (perms.canReadMembers()) {
+                dependencies.membersManager.loadMembers(id)
+            }
+        }
+    }
+
+    /** Nach Netzwerk-Wiederkehr Listen neu laden (Server ist Quelle der Wahrheit). */
+    LaunchedEffect(networkConnected, clubState.currentClubId, clubState.currentPermissions) {
+        val id = clubState.currentClubId ?: return@LaunchedEffect
+        val perms = clubState.currentPermissions ?: return@LaunchedEffect
+        val wasConnected = lastNetworkConnected
+        lastNetworkConnected = networkConnected
+        if (!wasConnected && networkConnected) {
+            dependencies.applicationScope.launch {
+                if (perms.canReadDiary()) {
+                    dependencies.diaryManager.loadDates(id)
+                }
+                if (perms.canReadMembers()) {
+                    dependencies.membersManager.loadMembers(id)
+                }
+            }
+        }
+    }
 
     LaunchedEffect(selectedTab) {
         if (selectedTab != MainTab.Settings) {
@@ -1462,6 +1496,14 @@ private fun DiaryListScreen(
             .padding(horizontal = ScreenHorizontalPadding, vertical = 16.dp),
     ) {
         Header(tr("diary.title", "Tagebuch"))
+        if (diaryState.fromOfflineCache) {
+            Text(
+                tr("mobile.offlineCacheHint", "Keine Verbindung – zuletzt geladene Daten."),
+                style = MaterialTheme.typography.caption,
+                color = MaterialTheme.colors.onSurface.copy(alpha = 0.65f),
+                modifier = Modifier.padding(bottom = 8.dp),
+            )
+        }
         Text(
             tr("diary.listHintCompact", "Trainingstag wählen und direkt bearbeiten."),
             style = MaterialTheme.typography.body2,
@@ -4502,6 +4544,14 @@ private fun MembersScreen(
                     .padding(horizontal = ScreenHorizontalPadding, vertical = 16.dp),
             ) {
                 Header(tr("members.title", "Mitglieder"))
+                if (membersState.fromOfflineCache) {
+                    Text(
+                        trStr("mobile.offlineCacheHint", "Keine Verbindung – zuletzt geladene Daten."),
+                        style = MaterialTheme.typography.caption,
+                        color = MaterialTheme.colors.onSurface.copy(alpha = 0.65f),
+                        modifier = Modifier.padding(bottom = 8.dp),
+                    )
+                }
                 Row(
                     modifier = Modifier.fillMaxWidth().padding(bottom = 8.dp),
                     horizontalArrangement = Arrangement.spacedBy(8.dp),