chatgui: fix NodesPage truncated Node ID + add DB diagnostics

- NodesPage: show full 64-bit Node ID (hex16) instead of truncated 4 hex chars
- NodesPage: show diagnostic when DB handle is NULL (was silent return)
- DatabaseSettingsPage: show 'Database not connected' when DB handle is NULL
- DatabaseSettingsPage: add refreshStatus() called on tab select
- SettingsDialog: refresh Database tab on category change

tools/chatgui/src/databasesettingspage.cpp

@@ -127,6 +127,48 @@ DatabaseSettingsPage::DatabaseSettingsPage(DbManager* db, QWidget* parent)
     layout->addWidget(m_resultText);
 
     layout->addStretch();
+
+    if (!m_db || !m_db->m_db) {
+        m_statusLabel->setText("Database not connected");
+        m_statusLabel->setStyleSheet("font-size: 12px; font-weight: bold; color: red;");
+        m_quickBtn->setEnabled(false);
+        m_fullBtn->setEnabled(false);
+        m_optimizeBtn->setEnabled(false);
+        qWarning("DatabaseSettingsPage: DB not ready m_db=%p m_db->m_db=%p", (void*)m_db, m_db ? (void*)m_db->m_db : nullptr);
+    }
+}
+
+void DatabaseSettingsPage::refreshStatus() {
+    if (!m_db || !m_db->m_db) {
+        m_statusLabel->setText("Database not connected");
+        m_statusLabel->setStyleSheet("font-size: 12px; font-weight: bold; color: red;");
+        m_quickBtn->setEnabled(false);
+        m_fullBtn->setEnabled(false);
+        m_optimizeBtn->setEnabled(false);
+        return;
+    }
+    m_quickBtn->setEnabled(true);
+    m_fullBtn->setEnabled(true);
+    m_optimizeBtn->setEnabled(true);
+    const char* fname = sqlite3_db_filename(m_db->m_db, "main");
+    if (fname && fname[0]) {
+        QString dbPath = QString::fromUtf8(fname);
+        m_filePathLabel->setText(dbPath);
+        QFileInfo fi(dbPath);
+        if (fi.exists()) {
+            qint64 sz = fi.size();
+            if (sz < 1024) m_fileSizeLabel->setText(QString("%1 B").arg(sz));
+            else if (sz < 1024 * 1024) m_fileSizeLabel->setText(QString("%1 KB").arg(sz / 1024));
+            else m_fileSizeLabel->setText(QString("%1 MB").arg(sz / (1024.0 * 1024.0), 0, 'f', 2));
+            QFileInfo walFi(dbPath + "-wal");
+            if (walFi.exists()) {
+                qint64 wsz = walFi.size();
+                if (wsz < 1024) m_walSizeLabel->setText(QString("%1 B").arg(wsz));
+                else if (wsz < 1024 * 1024) m_walSizeLabel->setText(QString("%1 KB").arg(wsz / 1024));
+                else m_walSizeLabel->setText(QString("%1 MB").arg(wsz / (1024.0 * 1024.0), 0, 'f', 2));
+            } else { m_walSizeLabel->setText("n/a"); }
+        }
+    }
 }
 
 void DatabaseSettingsPage::setBusy(bool busy) {

tools/chatgui/src/databasesettingspage.h

@@ -12,6 +12,7 @@ class DatabaseSettingsPage : public QWidget {
     Q_OBJECT
 public:
     explicit DatabaseSettingsPage(DbManager* db, QWidget* parent = nullptr);
+    void refreshStatus();
 
 private slots:
     void onQuickCheck();

tools/chatgui/src/nodespage.cpp

@@ -12,8 +12,8 @@
 
 #include "../../../lib/platform_compat.h"
 
-static QString hex4(uint32_t v) {
-    return QString("%1").arg(v, 4, 16, QChar('0')).toUpper();
+static QString hex16(uint64_t v) {
+    return QString("%1").arg(v, 16, 16, QChar('0')).toUpper();
 }
 
 QString NodesPage::shortenKey(const QByteArray& key) {
@@ -106,7 +106,13 @@ NodesPage::NodesPage(DbManager* db, QWidget* parent)
 void NodesPage::onRefreshClicked() { refreshNodes(); }
 
 void NodesPage::refreshNodes() {
-    if (!m_db || !m_db->m_db) return;
+    if (!m_db || !m_db->m_db) {
+        m_table->setRowCount(0);
+        m_dumpText->setPlainText(QString("Database not connected (m_db=%1, m_db->m_db=%2)")
+            .arg((quintptr)m_db, 0, 16).arg(m_db ? (quintptr)m_db->m_db : 0, 0, 16));
+        qWarning("NodesPage::refreshNodes: DB not ready m_db=%p m_db->m_db=%p", (void*)m_db, m_db ? (void*)m_db->m_db : nullptr);
+        return;
+    }
 
     sqlite3* d = m_db->m_db;
 
@@ -128,7 +134,7 @@ void NodesPage::refreshNodes() {
             m_table->setItem(row, col, new QTableWidgetItem(v));
         };
 
-        setCell(0, hex4((uint32_t)(nid & 0xFFFF)));
+        setCell(0, hex16(nid));
         setCell(1, DbManager::colText(st, 1));
         setCell(2, sqlite3_column_int(st, 2) ? "yes" : "no");
 
@@ -176,7 +182,7 @@ void NodesPage::refreshNodes() {
         qint64 last_seen = sqlite3_column_int64(st, 5);
         qint64 created = sqlite3_column_int64(st, 6);
 
-        dump += QString("Node: %1").arg(hex4((uint32_t)(nid & 0xFFFF)));
+        dump += QString("Node: %1").arg(hex16(nid));
         if (!name.isEmpty()) dump += QString(" (%1)").arg(name);
         dump += QString("  id=0x%1\n").arg(nid, 16, 16, QChar('0'));
         dump += QString("  online: %1\n").arg(online ? "yes" : "no");

tools/chatgui/src/settingsdialog.cpp

@@ -139,6 +139,7 @@ void SettingsDialog::loadProfileFromConfig(const QString& path) {
 
 void SettingsDialog::onCategoryChanged(int row) {
     m_pages->setCurrentIndex(row);
+    if (row == 2) m_databasePage->refreshStatus();
     if (row == 3) m_statusPage->refreshStatus();
     if (row == 4) m_nodesPage->refreshNodes();
 }