feat: füge ConnectivityTracker hinzu, erweitere networkModule, aktualisiere DesktopFooterBar mit Gerätestatus und mDNS-Discovery

Signed-off-by: StefanMoCoAt <stefan.mo.co@gmail.com>

frontend/core/network/src/commonMain/kotlin/at/mocode/frontend/core/network/ConnectivityTracker.kt

@@ -0,0 +1,48 @@
+package at.mocode.frontend.core.network
+
+import io.ktor.client.*
+import io.ktor.client.request.*
+import kotlinx.coroutines.*
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import org.koin.core.component.KoinComponent
+import org.koin.core.component.inject
+import org.koin.core.qualifier.named
+
+/**
+ * Überwacht die Konnektivität zum API-Gateway.
+ */
+class ConnectivityTracker : KoinComponent {
+  private val client: HttpClient by inject(named("baseHttpClient"))
+  private val _isOnline = MutableStateFlow(true)
+  val isOnline: StateFlow<Boolean> = _isOnline.asStateFlow()
+
+  private val scope = CoroutineScope(Dispatchers.Default + SupervisorJob())
+
+  init {
+    startTracking()
+  }
+
+  private fun startTracking() {
+    scope.launch {
+      while (isActive) {
+        _isOnline.value = checkConnection()
+        delay(10_000) // Alle 10 Sekunden prüfen
+      }
+    }
+  }
+
+  private suspend fun checkConnection(): Boolean {
+    return try {
+      val response = client.get(NetworkConfig.baseUrl.trimEnd('/') + "/ping")
+      response.status.value in 200..299
+    } catch (e: Exception) {
+      false
+    }
+  }
+
+  fun stopTracking() {
+    scope.cancel()
+  }
+}

frontend/core/network/src/commonMain/kotlin/at/mocode/frontend/core/network/NetworkModule.kt

@@ -1,5 +1,7 @@
 package at.mocode.frontend.core.network
 
+import at.mocode.frontend.core.network.discovery.discoveryModule
+import at.mocode.frontend.core.network.sync.syncModule
 import io.ktor.client.*
 import io.ktor.client.plugins.*
 import io.ktor.client.plugins.contentnegotiation.*
@@ -10,13 +12,13 @@ import kotlinx.serialization.json.Json
 import org.koin.core.module.Module
 import org.koin.core.qualifier.named
 import org.koin.dsl.module
-import at.mocode.frontend.core.network.discovery.discoveryModule
-import at.mocode.frontend.core.network.sync.syncModule
 
 /**
  * Schnittstelle zur Token-Bereitstellung – entkoppelt core-network von core-auth.
  */
-interface TokenProvider { fun getAccessToken(): String? }
+interface TokenProvider {
+  fun getAccessToken(): String?
+}
 
 /**
  * Koin-Modul mit zwei HttpClient-Instanzen:
@@ -26,6 +28,8 @@ interface TokenProvider { fun getAccessToken(): String? }
 val networkModule: Module = module {
   includes(discoveryModule, syncModule)
 
+  single<ConnectivityTracker> { ConnectivityTracker() }
+
   // 1. Basis-Client (für Auth-Endpunkte, ohne Bearer-Token)
   single(named("baseHttpClient")) {
     HttpClient {