Show private conversation start failures and test stale confirmation isolation

tools/chatgui-android/app/src/main/java/com/utun/chat/ui/screens/MemberListScreen.kt

@@ -78,6 +78,7 @@ fun MemberListScreen(
     val localSockets by viewModel.localSockets.collectAsState()
     val channelOwner by viewModel.channelOwner.collectAsState()
     val radioMuteFailed by viewModel.radioMuteFailed.collectAsState()
+    val dmStartFailed by viewModel.dmStartFailed.collectAsState()
     val radioActive by viewModel.radioActive.collectAsState()
     val radioTalkState by viewModel.radioTalkState.collectAsState()
     val transmittingGroup by viewModel.radioAudio.transmittingGroup.collectAsState()
@@ -156,6 +157,11 @@ fun MemberListScreen(
             confirmButton = { TextButton(onClick = viewModel::dismissRadioMuteError) { Text(stringResource(android.R.string.ok)) } }
         )
     }
+    if (dmStartFailed) AlertDialog(
+        onDismissRequest = viewModel::dismissDmStartError,
+        text = { Text(stringResource(R.string.invite_pm_start_failed)) },
+        confirmButton = { TextButton(onClick = viewModel::dismissDmStartError) { Text(stringResource(android.R.string.ok)) } }
+    )
 
     val editingMember = editMember
     if (showEditDialog && editingMember != null) key(channel.id, editingMember.nodeId) {

tools/chatgui-android/app/src/main/java/com/utun/chat/viewmodel/ChatViewModel.kt

@@ -1339,7 +1339,9 @@ class ChatViewModel : ViewModel() {
     }
 
     fun startDm(channelId: String, nodeId: Long, name: String) {
-        val r = repo ?: return
+        val r = repo ?: run {
+            _dmStartFailed.value = true; LogManager.addLog("WARN", "PM", "Conversation start rejected: repository unavailable"); return
+        }
         if (nodeId == 0L || nodeId == NativeLib.getMyNodeId()) return
         cancelDmStart(); _dmStartFailed.value = false
         try {

tools/chatgui-android/app/src/test/java/com/utun/chat/data/PendingDmOpenTest.kt

@@ -0,0 +1,43 @@
+package com.utun.chat.data
+
+import org.junit.Assert.*
+import org.junit.Test
+
+class PendingDmOpenTest {
+    @Test fun unrelatedConversationDoesNotConsumeRequestedPeer() {
+        val pending = PendingDmOpen()
+        val token = pending.begin("51", 12, "requested")
+        assertNull(pending.complete("99", 7))
+        assertTrue(pending.isPending(token))
+        val selected = pending.complete("51", 9)!!
+        assertEquals("51", selected.convId)
+        assertEquals(12L, selected.peerNodeId)
+        assertEquals("requested", selected.peerName)
+        assertEquals(9L, selected.generation)
+        assertFalse(pending.pending)
+        assertNull(pending.complete("51", 10))
+    }
+    @Test fun newRequestRejectsOldConfirmationAndTimeout() {
+        val pending = PendingDmOpen()
+        val previous = pending.begin("51", 12, "first")
+        val current = pending.begin("52", 13, "second")
+        assertFalse(pending.isPending(previous))
+        assertNull(pending.complete("51", 1))
+        assertTrue(pending.isPending(current))
+        assertEquals(13L, pending.complete("52", 2)!!.peerNodeId)
+    }
+    @Test fun navigationOrTimeoutCancellationIgnoresLateConfirmation() {
+        val pending = PendingDmOpen()
+        val token = pending.begin("51", 12, "first")
+        pending.cancel()
+        assertFalse(pending.isPending(token))
+        assertNull(pending.complete("51", 1))
+    }
+    @Test fun invalidGenerationKeepsPendingValidConfirmation() {
+        val pending = PendingDmOpen()
+        pending.begin("51", 12, "first")
+        assertNull(pending.complete("51", 0))
+        assertTrue(pending.pending)
+        assertNotNull(pending.complete("51", 1))
+    }
+}