feat/Implement QR code generation and scanning

client/core/controllers/api/pairingController.h

@@ -0,0 +1,45 @@
+#ifndef PAIRINGCONTROLLER_H
+#define PAIRINGCONTROLLER_H
+
+#include <QJsonArray>
+#include <QJsonObject>
+#include <QString>
+
+#include "core/utils/errorCodes.h"
+
+class SecureAppSettingsRepository;
+
+/**
+ * Core API for QR pairing against Amnezia gateway (POST /api/v1/generate_qr, /api/v1/scan_qr).
+ * Phase 1: transport via GatewayController, error mapping incl. gateway `http_status` wrapper and OpenAPI-style bodies.
+ */
+class PairingController
+{
+public:
+    struct QrPairingConfigPayload
+    {
+        QString config;
+        QJsonObject serviceInfo;
+        QJsonArray supportedProtocols;
+    };
+
+    explicit PairingController(SecureAppSettingsRepository *appSettingsRepository);
+
+    int pairingLongPollTimeoutMsecs() const;
+
+    QJsonObject buildGenerateQrPayload(const QString &qrUuid) const;
+    QJsonObject buildScanQrPayload(const QString &qrUuid, const QString &vpnConfig, const QJsonObject &serviceInfo,
+                                   const QJsonArray &supportedProtocols, const QString &apiKey) const;
+
+    static amnezia::ErrorCode parseGenerateQrResponseBody(const QByteArray &responseBody, QrPairingConfigPayload &outPayload);
+    static amnezia::ErrorCode parseScanQrResponseBody(const QByteArray &responseBody);
+
+    amnezia::ErrorCode startPairing(const QString &qrUuid, QrPairingConfigPayload &outPayload);
+    amnezia::ErrorCode completePairing(const QString &qrUuid, const QString &vpnConfig, const QJsonObject &serviceInfo,
+                                       const QJsonArray &supportedProtocols, const QString &apiKey);
+
+private:
+    SecureAppSettingsRepository *m_appSettingsRepository;
+};
+
+#endif // PAIRINGCONTROLLER_H