fix(chat): node online status race, WELCOME peer_needed off-by-one, JOIN missing proto byte

- node_put/node_update_verified: set online=1 on INSERT (nodes created when conn is UP)
- channel_peers_all: fix peer_needed calculation (atl byte was missing)
- cs_send_channel_join: add proto byte to address serialization matching all parsers

tools/chatgui/db/db_manager.cpp

@@ -229,6 +229,33 @@ QList<MessageRow> DbManager::getMessagesSince(const QString& chId, qint64 sinceI
     return list;
 }
 
+MessageRow DbManager::getMessageById(const QString& chId, qint64 msgId) const {
+    MessageRow m;
+    QString sql = QStringLiteral(
+        "SELECT id, node_id, data, timestamp, chain_hash, author_signature, local_attrs"
+        " FROM \"%1\" WHERE id = ?").arg(msgTableName(chId));
+    sqlite3_stmt* stmt = prepareOrNull(sql.toUtf8().constData());
+    if (!stmt) return m;
+    sqlite3_bind_int64(stmt, 1, msgId);
+    if (sqlite3_step(stmt) == SQLITE_ROW) {
+        m.id           = sqlite3_column_int64(stmt, 0);
+        m.authorNodeId = (quint64)sqlite3_column_int64(stmt, 1);
+        QByteArray jdata = colBlob(stmt, 2);
+        m.contentType  = QString::fromUtf8(parseJsonField(jdata, "ct"));
+        if (m.contentType.isEmpty()) m.contentType = "text/plain";
+        m.data         = parseJsonField(jdata, "d");
+        m.timestamp    = sqlite3_column_int64(stmt, 3);
+        m.datahash     = 0;
+        m.chainHash    = colBlob(stmt, 4);
+        m.signature    = colBlob(stmt, 5);
+        m.localAttrs   = QByteArray((const char*)sqlite3_column_text(stmt, 6));
+        m.isOutgoing   = (m.authorNodeId == m_myNodeId);
+        m.isRead       = true;
+    }
+    sqlite3_finalize(stmt);
+    return m;
+}
+
 /* ── peers (UI) ── */
 
 int DbManager::getChannelMemberCount(const QString& chId) const {