console and mining tab visual improvements

src/app.h

@@ -11,6 +11,7 @@
 #include <atomic>
 #include <chrono>
 #include "data/wallet_state.h"
+#include "rpc/connection.h"
 #include "ui/sidebar.h"
 #include "ui/windows/console_tab.h"
 #include "imgui.h"
@@ -20,7 +21,6 @@ namespace dragonx {
     namespace rpc { 
         class RPCClient;
         class RPCWorker;
-        struct ConnectionConfig;
     }
     namespace config { class Settings; }
     namespace daemon { class EmbeddedDaemon; class XmrigManager; }
@@ -79,6 +79,15 @@ public:
      */
     void update();
 
+    /**
+     * @brief Pre-frame tasks that must run BEFORE ImGui::NewFrame().
+     *
+     * Font atlas rebuilds (hot-reload, user font scale changes) must
+     * happen before NewFrame() because NewFrame() caches font pointers.
+     * Rebuilding mid-frame causes dangling pointer crashes.
+     */
+    void preFrame();
+
     /**
      * @brief Render the application UI (called every frame)
      */
@@ -313,6 +322,16 @@ private:
     // Subsystems
     std::unique_ptr<rpc::RPCClient> rpc_;
     std::unique_ptr<rpc::RPCWorker> worker_;
+
+    // Fast-lane: dedicated RPC connection + worker for 1-second mining polls.
+    // Runs on its own thread with its own curl handle so it never blocks behind
+    // the main refresh batch.
+    std::unique_ptr<rpc::RPCClient> fast_rpc_;
+    std::unique_ptr<rpc::RPCWorker> fast_worker_;
+
+    // Saved connection credentials (needed to open the fast-lane connection)
+    rpc::ConnectionConfig saved_config_;
+
     std::unique_ptr<config::Settings> settings_;
     std::unique_ptr<daemon::EmbeddedDaemon> embedded_daemon_;
     std::unique_ptr<daemon::XmrigManager> xmrig_manager_;