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

src/routing_layer/topo_node.c

@@ -363,7 +363,7 @@ void topo_node_ping_update_rtt(struct TOPO_GROUPS* groups, uint64_t node_id, uin
                 nq->connectivity.nat_min_rtt = rtt;
             if (nq->connectivity.real_min_rtt == 0 || rtt < nq->connectivity.real_min_rtt)
                 nq->connectivity.real_min_rtt = rtt;
-            DEBUG_INFO(DEBUG_CATEGORY_BGP, "ping_update_rtt: node=%016llx rtt=%u (%llu) group=%016llx",
+            DEBUG_DEBUG(DEBUG_CATEGORY_BGP, "ping_update_rtt: node=%016llx rtt=%u (%llu) group=%016llx",
                        (unsigned long long)node_id, (unsigned)rtt, (unsigned long long)now, (unsigned long long)g->group_id);
             if (groups->instance && groups->instance->topo_sqlite_db)
                 topo_node_sqlite_update_rtt(groups->instance->topo_sqlite_db, node_id, rtt);