android: fix QR join flow + cleanup log levels + remove log artifacts

- MainActivity: call NativeLib.joinChannel directly (bypass ViewModel null repo)
- LogManager: add Log.d for Kotlin logs visibility in logcat
- ChatViewModel/NativeLib: add diagnostic logs for join path
- chat_sync: JNI-safe logs via __android_log_print, add error on !g_cs
- etcp_debug: DUMP INFO→DEBUG (remove 99.8% packet spam)
- secure_channel/etcp_connections/topo_node: keepalive PING/PONG spam INFO→DEBUG
- .gitignore: logreceiver output + build artifacts
- Remove tracked log files and build dir from repo

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

@@ -100,7 +100,7 @@ class MainActivity : ComponentActivity() {
                     },
                     onConnect = { data: InviteData ->
                         val addrs = data.serializeAddrs()
-                        vm.joinChannel(data.channelId, data.nodeId, data.pubkey, addrs, data.addrs.size)
+                        NativeLib.joinChannel(data.channelId, data.nodeId, data.pubkey, addrs, data.addrs.size)
                         showJoinDialog = false
                     },
                     onDismiss = { showJoinDialog = false }

tools/chatgui-android/app/src/main/java/com/utun/chat/data/LogManager.kt

@@ -1,5 +1,6 @@
 package com.utun.chat.data
 
+import android.util.Log
 import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.SharedFlow
 import kotlinx.coroutines.flow.asSharedFlow
@@ -19,6 +20,7 @@ object LogManager {
 
     @Synchronized
     fun addLog(level: String, category: String, message: String) {
+        Log.d("utun-gui", "[$level] [$category] $message")
         val entry = LogEntry(level = level, category = category, message = message)
         if (_buffer.size >= MAX_BUFFER) _buffer.removeFirst()
         _buffer.add(entry)

tools/chatgui-android/app/src/main/java/com/utun/chat/data/NativeLib.kt

@@ -59,7 +59,9 @@ object NativeLib {
     fun createChannel(name: String, channelId: String) { nativeCreateChannel(name, channelId) }
     fun connectNode(address: String, port: Int, pubkeyHex: String) { nativeConnectNode(address, port, pubkeyHex) }
     fun joinChannel(channelId: Long, nodeId: Long, pubkey: ByteArray, addrs: ByteArray, addrCount: Int) {
+        LogManager.addLog("INFO", "JNI", "joinChannel: calling native")
         nativeJoinChannel(channelId, nodeId, pubkey, addrs, addrCount)
+        LogManager.addLog("INFO", "JNI", "joinChannel: native returned")
     }
     fun connectChannel(channelId: String) { nativeConnectChannel(channelId) }
     fun getChannels(): String = nativeGetChannels() ?: "[]"

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

@@ -136,7 +136,9 @@ class ChatViewModel : ViewModel() {
     }
 
     fun joinChannel(channelId: Long, nodeId: Long, pubkey: ByteArray, addrs: ByteArray, addrCount: Int) {
-        val r = repo ?: return
+        val r = repo
+        if (r == null) { LogManager.addLog("ERROR", "VM", "joinChannel: repo is NULL"); return }
+        LogManager.addLog("INFO", "VM", "joinChannel: ch=0x%016x node=0x%016x".format(channelId, nodeId))
         r.joinChannel(channelId, nodeId, pubkey, addrs, addrCount)
     }