docs(journal): Session-Log zu P2P-Guards, FilePicker-Fixes und Tests hinzugefügt

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

frontend/core/design-system/src/jvmMain/kotlin/at/mocode/frontend/core/designsystem/components/MsFilePicker.jvm.kt

@@ -78,6 +78,9 @@ actual fun MsFilePicker(
         SwingUtilities.invokeLater {
           val chooser = JFileChooser().apply {
             isMultiSelectionEnabled = false
+            isAcceptAllFileFilterUsed = false
+            approveButtonText = "Auswählen"
+            
             // Initiales Verzeichnis/Pfad
             run {
               val home = File(System.getProperty("user.home") ?: ".")
@@ -108,7 +111,7 @@ actual fun MsFilePicker(
             }
           }
 
-          val result = chooser.showDialog(null, "Auswählen")
+          val result = chooser.showOpenDialog(null)
           if (result == JFileChooser.APPROVE_OPTION) {
             val chosen = chooser.selectedFile
             if (directoryOnly) {

frontend/core/network/build.gradle.kts

@@ -51,5 +51,10 @@ kotlin {
       implementation(libs.ktor.client.js)
       implementation(libs.kotlinx.coroutines.core)
     }
+
+    commonTest.dependencies {
+      implementation(libs.kotlin.test)
+      implementation(libs.kotlinx.coroutines.test)
+    }
   }
 }

frontend/core/network/src/jvmTest/kotlin/at/mocode/frontend/core/network/sync/JvmP2pSyncServiceTest.kt

@@ -0,0 +1,37 @@
+package at.mocode.frontend.core.network.sync
+
+import kotlinx.coroutines.test.runTest
+import kotlin.test.Test
+
+class JvmP2pSyncServiceTest {
+
+    @Test
+    fun starting_server_twice_on_same_port_should_not_fail_but_use_guard() = runTest {
+        val service1 = JvmP2pSyncService()
+        val service2 = JvmP2pSyncService()
+        val port = 9091
+
+        try {
+            service1.startServer(port)
+            // Second start should just return/log and not throw an exception (idempotent)
+            service2.startServer(port)
+        } finally {
+            service1.stopServer()
+            service2.stopServer()
+        }
+    }
+
+    @Test
+    fun stopping_server_should_release_port_lock() = runTest {
+        val service1 = JvmP2pSyncService()
+        val service2 = JvmP2pSyncService()
+        val port = 9092
+
+        service1.startServer(port)
+        service1.stopServer()
+
+        // After stopping, starting again on same port (even from different instance) should work
+        service2.startServer(port)
+        service2.stopServer()
+    }
+}