Initial Bobink library: BobinkAuth, BobinkClient, and demo app

Implements the core OPC UA wrapper library with:
- Build system with automatic dep building (open62541, QtOpcUa)
- BobinkAuth: QML auth component (anonymous/userpass/certificate)
- BobinkClient: QML singleton managing connection, LDS discovery,
  PKI configuration, endpoint selection, and certificate trust flow
- Demo app for manual testing of the full connection flow

1 files changed, 123 insertions, 0 deletions

diff --git a/src/BobinkClient.h b/src/BobinkClient.h
new file mode 100644
index 0000000..b8e5624
--- /dev/null
+++ b/src/BobinkClient.h
@@ -0,0 +1,123 @@
+#ifndef BOBINKCLIENT_H
+#define BOBINKCLIENT_H
+
+#include <QEventLoop>
+#include <QObject>
+#include <QOpcUaApplicationDescription>
+#include <QOpcUaClient>
+#include <QOpcUaEndpointDescription>
+#include <QOpcUaErrorState>
+#include <QOpcUaPkiConfiguration>
+#include <QOpcUaProvider>
+#include <QQmlEngine>
+#include <QTimer>
+
+class BobinkAuth;
+
+class BobinkClient : public QObject
+{
+  Q_OBJECT
+  QML_ELEMENT
+  QML_SINGLETON
+
+  Q_PROPERTY (bool connected READ connected NOTIFY connectedChanged)
+  Q_PROPERTY (QString serverUrl READ serverUrl WRITE setServerUrl NOTIFY
+                  serverUrlChanged)
+  Q_PROPERTY (BobinkAuth *auth READ auth WRITE setAuth NOTIFY authChanged)
+
+  Q_PROPERTY (QString discoveryUrl READ discoveryUrl WRITE setDiscoveryUrl
+                  NOTIFY discoveryUrlChanged)
+  Q_PROPERTY (int discoveryInterval READ discoveryInterval WRITE
+                  setDiscoveryInterval NOTIFY discoveryIntervalChanged)
+  Q_PROPERTY (bool discovering READ discovering NOTIFY discoveringChanged)
+  Q_PROPERTY (QVariantList servers READ servers NOTIFY serversChanged)
+
+  Q_PROPERTY (QString pkiDir READ pkiDir WRITE setPkiDir NOTIFY pkiDirChanged)
+
+public:
+  explicit BobinkClient (QObject *parent = nullptr);
+  ~BobinkClient () override;
+
+  static BobinkClient *instance ();
+  static BobinkClient *create (QQmlEngine *qmlEngine, QJSEngine *jsEngine);
+
+  bool connected () const;
+
+  QString serverUrl () const;
+  void setServerUrl (const QString &url);
+
+  BobinkAuth *auth () const;
+  void setAuth (BobinkAuth *auth);
+
+  QOpcUaClient *opcuaClient () const;
+
+  QString discoveryUrl () const;
+  void setDiscoveryUrl (const QString &url);
+
+  int discoveryInterval () const;
+  void setDiscoveryInterval (int ms);
+
+  bool discovering () const;
+
+  const QList<QOpcUaApplicationDescription> &discoveredServers () const;
+  QVariantList servers () const;
+
+  QString pkiDir () const;
+  void setPkiDir (const QString &path);
+
+  Q_INVOKABLE void connectToServer ();
+  Q_INVOKABLE void disconnectFromServer ();
+  Q_INVOKABLE void acceptCertificate ();
+  Q_INVOKABLE void rejectCertificate ();
+
+  Q_INVOKABLE void startDiscovery ();
+  Q_INVOKABLE void stopDiscovery ();
+  Q_INVOKABLE void applyPki ();
+
+signals:
+  void connectedChanged ();
+  void serverUrlChanged ();
+  void authChanged ();
+  void certificateTrustRequested (const QString &certInfo);
+  void connectionError (const QString &message);
+
+  void discoveryUrlChanged ();
+  void discoveryIntervalChanged ();
+  void discoveringChanged ();
+  void serversChanged ();
+  void pkiDirChanged ();
+
+private slots:
+  void handleStateChanged (QOpcUaClient::ClientState state);
+  void
+  handleEndpointsReceived (const QList<QOpcUaEndpointDescription> &endpoints,
+                           QOpcUa::UaStatusCode statusCode,
+                           const QUrl &requestUrl);
+  void handleConnectError (QOpcUaErrorState *errorState);
+  void handleFindServersFinished (
+      const QList<QOpcUaApplicationDescription> &servers,
+      QOpcUa::UaStatusCode statusCode, const QUrl &requestUrl);
+  void doDiscovery ();
+
+private:
+  void setupClient ();
+
+  static BobinkClient *s_instance;
+  QOpcUaProvider *m_provider = nullptr;
+  QOpcUaClient *m_client = nullptr;
+  BobinkAuth *m_auth = nullptr;
+  QString m_serverUrl;
+  bool m_connected = false;
+  QEventLoop *m_certLoop = nullptr;
+  bool m_certAccepted = false;
+
+  QString m_discoveryUrl;
+  int m_discoveryInterval = 10000;
+  QTimer m_discoveryTimer;
+  bool m_discovering = false;
+  QList<QOpcUaApplicationDescription> m_discoveredServers;
+
+  QString m_pkiDir;
+};
+
+#endif // BOBINKCLIENT_H