feat(lite): Console tab with connection + open/create diagnostics

The lite variant had no visibility into why a wallet failed to open — just a
"disconnected" spinner. Add a lite-only Console tab (full-node keeps its RPC
console) that shows a live diagnostic log.

- LiteDiagnostics: a small thread-safe, bounded ring buffer (header-only). The
  controller writes to it from its background threads: each failover server
  attempt and result, wallet open/create/restore outcomes, sync start, and
  blocked-open reasons. The App logs controller (re)builds with the preferred
  server.
- lite_console_tab: a terminal-styled, read-only view of the log (newest at the
  bottom, error/success lines coloured) with Clear / Copy / Auto-scroll. Reachable
  even when the wallet is locked (it's diagnostics, no secrets). Registered as
  NavPage::LiteConsole, gated lite-only via WalletUiSurface::LiteConsole.

A unit test drives an open-with-failover and asserts the log records the
connection attempt and the successful open. Built clean for full-node, lite, and
Windows cross-compile.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

CMakeLists.txt

@@ -440,6 +440,7 @@ set(APP_SOURCES
     src/ui/windows/mining_tab_helpers.cpp
     src/ui/windows/peers_tab.cpp
     src/ui/windows/network_tab.cpp
+    src/ui/windows/lite_console_tab.cpp
     src/ui/windows/explorer_tab.cpp
     src/ui/windows/market_tab.cpp
     src/ui/windows/console_tab.cpp

src/app.cpp

@@ -14,6 +14,7 @@
 #include "wallet/lite_wallet_controller.h"
 #include "wallet/lite_wallet_server_selection_adapter.h"
 #include "wallet/lite_rollout_policy.h"
+#include "wallet/lite_diagnostics.h"
 
 #include <cstdlib>  // std::getenv for the lite kill-switch env var
 #include <sodium.h>  // sodium_memzero for the lite unlock-passphrase buffer
@@ -29,6 +30,7 @@
 #include "ui/windows/mining_tab.h"
 #include "ui/windows/peers_tab.h"
 #include "ui/windows/network_tab.h"
+#include "ui/windows/lite_console_tab.h"
 #include "ui/windows/explorer_tab.h"
 #include "ui/windows/market_tab.h"
 #include "ui/windows/settings_window.h"
@@ -443,10 +445,11 @@ void App::rebuildLiteWallet(bool force)
     // does not block. The app's auto-open loop then reopens the wallet against the new server.
     if (!force && lite_wallet_ && lite_wallet_->walletOpen()) return;
 
+    const auto liteConn = wallet::liteConnectionSettingsFromAppSettings(*settings_);
+    wallet::liteLog(std::string(force ? "Lite controller rebuilt" : "Lite controller built") +
+                    " (preferred server: " + liteConn.stickyServerUrl + ")");
     lite_wallet_ = wallet::LiteWalletController::createLinked(
-        walletCapabilities(),
-        wallet::liteConnectionSettingsFromAppSettings(*settings_),
-        resolveLiteRolloutDecision(*settings_));
+        walletCapabilities(), liteConn, resolveLiteRolloutDecision(*settings_));
     lite_wallet_->setPersistCallback([this]() { settings_->save(); });
 
     // The new controller starts closed. Re-arm the one-shot auto-open so the next update()
@@ -1368,6 +1371,9 @@ void App::render()
         case ui::NavPage::LiteNetwork:
             ui::RenderLiteNetworkTab(this);
             break;
+        case ui::NavPage::LiteConsole:
+            ui::RenderLiteConsoleTab(this);
+            break;
         case ui::NavPage::Explorer:
             ui::RenderExplorerTab(this);
             break;

src/ui/sidebar.h

@@ -30,6 +30,7 @@ enum class NavPage {
     Market,
     // --- separator ---
     Console,
+    LiteConsole,   // lite-only diagnostics console (full-node uses the RPC Console); one per variant
     Peers,
     LiteNetwork,   // lite-only "Network" tab (full-node uses Peers); exactly one shows per variant
     Explorer,
@@ -52,9 +53,10 @@ inline const NavItem kNavItems[] = {
     { "History",   NavPage::History,  nullptr,    "history",  nullptr     },
     { "Mining",    NavPage::Mining,   "TOOLS",   "mining",   "tools"     },
     { "Market",    NavPage::Market,   nullptr,    "market",   nullptr     },
-    { "Console",   NavPage::Console,  "ADVANCED","console",  "advanced"  },
-    { "Network",   NavPage::Peers,       nullptr, "network",  nullptr     },
-    { "Network",   NavPage::LiteNetwork, nullptr, "network",  nullptr     },
+    { "Console",   NavPage::Console,     "ADVANCED","console",  "advanced"  },
+    { "Console",   NavPage::LiteConsole, "ADVANCED","console",  "advanced"  },
+    { "Network",   NavPage::Peers,       nullptr,   "network",  nullptr     },
+    { "Network",   NavPage::LiteNetwork, nullptr,   "network",  nullptr     },
     { "Explorer",  NavPage::Explorer, nullptr,    "explorer", nullptr     },
     { "Settings",  NavPage::Settings, nullptr,    "settings", nullptr     },
 };
@@ -79,6 +81,7 @@ inline wallet::WalletUiSurface NavPageSurface(NavPage page)
     case NavPage::Mining:   return wallet::WalletUiSurface::Mining;
     case NavPage::Market:   return wallet::WalletUiSurface::Market;
     case NavPage::Console:  return wallet::WalletUiSurface::Console;
+    case NavPage::LiteConsole: return wallet::WalletUiSurface::LiteConsole;
     case NavPage::Peers:    return wallet::WalletUiSurface::Peers;
     case NavPage::LiteNetwork: return wallet::WalletUiSurface::LiteNetwork;
     case NavPage::Explorer: return wallet::WalletUiSurface::Explorer;
@@ -103,6 +106,7 @@ inline const char* GetNavIconMD(NavPage page)
     case NavPage::Mining:    return ICON_MD_CONSTRUCTION;
     case NavPage::Market:    return ICON_MD_TRENDING_UP;
     case NavPage::Console:   return ICON_MD_TERMINAL;
+    case NavPage::LiteConsole: return ICON_MD_TERMINAL;
     case NavPage::Peers:     return ICON_MD_HUB;
     case NavPage::LiteNetwork: return ICON_MD_HUB;
     case NavPage::Explorer:  return ICON_MD_EXPLORE;
@@ -648,6 +652,7 @@ inline bool RenderSidebar(NavPage& current, float sidebarWidth, float contentHei
         // Click detection
         bool pageNeedsUnlock = locked &&
             item.page != NavPage::Console &&
+            item.page != NavPage::LiteConsole &&
             item.page != NavPage::Peers &&
             item.page != NavPage::Settings;
         if (hovered && ImGui::IsMouseClicked(ImGuiMouseButton_Left) && !pageNeedsUnlock) {

src/ui/windows/lite_console_tab.cpp

@@ -0,0 +1,98 @@
+// DragonX Wallet - ImGui Edition
+// Copyright 2024-2026 The Hush Developers
+// Released under the GPLv3
+
+#include "lite_console_tab.h"
+
+#include "../../app.h"
+#include "../../util/i18n.h"
+#include "../../wallet/lite_diagnostics.h"
+#include "../layout.h"
+#include "../material/type.h"
+#include "../material/colors.h"
+#include "imgui.h"
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace dragonx {
+namespace ui {
+
+using namespace material;
+
+namespace {
+
+// Re-snapshot the (mutex-guarded) log only when it actually changes, not every frame.
+std::vector<std::string> s_lines;
+std::uint64_t s_cachedGeneration = static_cast<std::uint64_t>(-1);
+bool s_autoScroll = true;
+
+// Colour error/success lines for at-a-glance scanning (substring match on the messages the
+// controller emits). Anything else renders in the muted default colour.
+ImU32 lineColor(const std::string& line)
+{
+    const auto has = [&line](const char* s) { return line.find(s) != std::string::npos; };
+    if (has("failed") || has(" unreachable") || has("blocked") || has("could not") ||
+        has("Error") || has("error"))
+        return Error();
+    if (has(": connected") || has("opened") || has("wallet ready") || has("Ready"))
+        return Success();
+    return OnSurfaceMedium();
+}
+
+}  // namespace
+
+void RenderLiteConsoleTab(App* app)
+{
+    (void)app;
+    auto& diag = wallet::LiteDiagnostics::instance();
+    const std::uint64_t gen = diag.generation();
+    if (gen != s_cachedGeneration) {
+        s_lines = diag.snapshot();
+        s_cachedGeneration = gen;
+    }
+
+    // ── Header ──────────────────────────────────────────────────────────────────
+    Type().text(TypeStyle::H6, TR("lite_console_title"));
+    Type().textColored(TypeStyle::Caption, OnSurfaceMedium(), TR("lite_console_intro"));
+    ImGui::Spacing();
+
+    // ── Toolbar ─────────────────────────────────────────────────────────────────
+    if (ImGui::Button(TR("lite_console_clear"))) diag.clear();
+    ImGui::SameLine();
+    if (ImGui::Button(TR("lite_console_copy"))) {
+        std::string all;
+        for (const auto& l : s_lines) { all += l; all.push_back('\n'); }
+        ImGui::SetClipboardText(all.c_str());
+    }
+    ImGui::SameLine();
+    ImGui::Checkbox(TR("lite_console_autoscroll"), &s_autoScroll);
+    ImGui::Spacing();
+
+    // ── Log (terminal-styled scroll region) ─────────────────────────────────────
+    ImGui::PushStyleColor(ImGuiCol_ChildBg, IM_COL32(0, 0, 0, 90));
+    ImGui::BeginChild("##LiteConsoleLog", ImVec2(0, 0), true,
+                      ImGuiWindowFlags_HorizontalScrollbar);
+    ImGui::PushFont(Type().caption());
+    if (s_lines.empty()) {
+        ImGui::PushStyleColor(ImGuiCol_Text, OnSurfaceDisabled());
+        ImGui::TextUnformatted(TR("lite_console_empty"));
+        ImGui::PopStyleColor();
+    } else {
+        for (const auto& line : s_lines) {
+            ImGui::PushStyleColor(ImGuiCol_Text, lineColor(line));
+            ImGui::TextUnformatted(line.c_str());  // not format-interpreted — safe for any content
+            ImGui::PopStyleColor();
+        }
+    }
+    // Keep pinned to the newest line only while the user is already at the bottom.
+    if (s_autoScroll && ImGui::GetScrollY() >= ImGui::GetScrollMaxY())
+        ImGui::SetScrollHereY(1.0f);
+    ImGui::PopFont();
+    ImGui::EndChild();
+    ImGui::PopStyleColor();
+}
+
+}  // namespace ui
+}  // namespace dragonx

src/ui/windows/lite_console_tab.h

@@ -0,0 +1,18 @@
+// DragonX Wallet - ImGui Edition
+// Copyright 2024-2026 The Hush Developers
+// Released under the GPLv3
+//
+// Lite-wallet "Console" tab: a read-only, terminal-styled view of the lite diagnostics log
+// (server connection attempts, wallet open/create/restore, sync milestones, errors). Lite
+// builds only. See src/ui/windows/lite_console_tab.cpp.
+
+#pragma once
+
+namespace dragonx {
+class App;
+namespace ui {
+
+void RenderLiteConsoleTab(App* app);
+
+} // namespace ui
+} // namespace dragonx

src/util/i18n.cpp

@@ -1107,6 +1107,12 @@ void I18n::loadBuiltinEnglish()
         strings_["xmrig_unknown_error"]      = "Unknown error.";
 
         // --- Lite Network tab (server browser) ---
+        strings_["lite_console_title"]      = "Console";
+        strings_["lite_console_intro"]      = "Diagnostic log: server connections, wallet open/create, and sync events.";
+        strings_["lite_console_clear"]      = "Clear";
+        strings_["lite_console_copy"]       = "Copy";
+        strings_["lite_console_autoscroll"] = "Auto-scroll";
+        strings_["lite_console_empty"]      = "No diagnostic output yet.";
         strings_["lite_net_title"]        = "Lite Servers";
         strings_["lite_net_intro"]        = "Pick a server to use, or let the wallet choose one at random. Changes apply immediately.";
         strings_["lite_net_use_random"]   = "Use a random server each time";

src/wallet/lite_diagnostics.h

@@ -0,0 +1,86 @@
+// DragonX Wallet - ImGui Edition
+// Copyright 2024-2026 The Hush Developers
+// Released under the GPLv3
+//
+// lite_diagnostics.h — a small, thread-safe in-memory log of lite-wallet diagnostic events
+// (server connection attempts, wallet open/create/restore, sync milestones, errors). Written
+// from the controller's background threads and the App; read by the lite Console tab. Bounded
+// so it can't grow without limit. Header-only (a Meyers singleton) so both the wallet layer
+// and the UI can use it with no extra link target.
+
+#pragma once
+
+#include <chrono>
+#include <cstdint>
+#include <cstdio>
+#include <ctime>
+#include <deque>
+#include <mutex>
+#include <string>
+#include <vector>
+
+namespace dragonx {
+namespace wallet {
+
+class LiteDiagnostics {
+public:
+    static LiteDiagnostics& instance() {
+        static LiteDiagnostics inst;
+        return inst;
+    }
+
+    // Append a timestamped line (thread-safe). Safe to call from background threads.
+    void log(const std::string& message) {
+        std::string line = timestamp();
+        line += message;
+        std::lock_guard<std::mutex> lk(mutex_);
+        lines_.push_back(std::move(line));
+        if (lines_.size() > kMaxLines) lines_.pop_front();
+        ++generation_;
+    }
+
+    // Copy of the current lines (oldest first).
+    std::vector<std::string> snapshot() const {
+        std::lock_guard<std::mutex> lk(mutex_);
+        return std::vector<std::string>(lines_.begin(), lines_.end());
+    }
+
+    // Monotonic counter bumped on every change — lets readers re-snapshot only when it differs.
+    std::uint64_t generation() const {
+        std::lock_guard<std::mutex> lk(mutex_);
+        return generation_;
+    }
+
+    void clear() {
+        std::lock_guard<std::mutex> lk(mutex_);
+        lines_.clear();
+        ++generation_;
+    }
+
+private:
+    LiteDiagnostics() = default;
+
+    static std::string timestamp() {
+        std::time_t t = std::time(nullptr);
+        std::tm tmv{};
+#ifdef _WIN32
+        localtime_s(&tmv, &t);
+#else
+        localtime_r(&t, &tmv);
+#endif
+        char buf[16];
+        std::snprintf(buf, sizeof(buf), "%02d:%02d:%02d  ", tmv.tm_hour, tmv.tm_min, tmv.tm_sec);
+        return std::string(buf);
+    }
+
+    static constexpr std::size_t kMaxLines = 500;
+    mutable std::mutex mutex_;
+    std::deque<std::string> lines_;
+    std::uint64_t generation_ = 0;
+};
+
+// Convenience: append a lite diagnostic line.
+inline void liteLog(const std::string& message) { LiteDiagnostics::instance().log(message); }
+
+}  // namespace wallet
+}  // namespace dragonx

src/wallet/lite_wallet_controller.cpp

@@ -4,6 +4,7 @@
 
 #include "lite_wallet_controller.h"
 
+#include "lite_diagnostics.h"
 #include "../data/wallet_state.h"
 
 #include <algorithm>
@@ -279,11 +280,16 @@ std::unique_ptr<LiteWalletController> LiteWalletController::createLinked(
 void LiteWalletController::onLifecycleResult(const LiteWalletLifecycleResult& result)
 {
     status_ = result.status;
+    const std::string op = liteWalletLifecycleOperationName(result.operation);
     if (result.walletReady) {
+        liteLog(op + ": wallet ready");
         walletOpen_ = true;
         if (persist_) persist_();
         startSync();    // begin background sync on the backend
         startWorker();  // begin periodic refresh -> WalletState (via takeRefreshedModel)
+    } else if (result.attempted) {
+        liteLog(op + " failed: " +
+                (result.error.empty() ? result.status.message : result.error));
     }
 }
 
@@ -312,6 +318,7 @@ bool LiteWalletController::beginOpenExisting()
         status_ = WalletBackendStatus{WalletBackendState::Error,
             reason.empty() ? "lite wallet is not available" : reason, {}, {}, 0.0};
         lastOpenError_ = status_.message;
+        liteLog("Open blocked: " + lastOpenError_);
         return false;
     }
     auto servers = failoverServerUrls();
@@ -319,6 +326,7 @@ bool LiteWalletController::beginOpenExisting()
         status_ = WalletBackendStatus{WalletBackendState::Error,
             "no usable lite servers are configured", {}, {}, 0.0};
         lastOpenError_ = status_.message;
+        liteLog("Open blocked: " + lastOpenError_);
         return false;
     }
 
@@ -329,6 +337,7 @@ bool LiteWalletController::beginOpenExisting()
     }
     openRunning_->store(true);
     status_ = WalletBackendStatus{WalletBackendState::Connecting, "opening wallet", {}, {}, 0.0};
+    liteLog("Opening wallet — trying " + std::to_string(servers.size()) + " server(s)");
 
     // Capture only shared refs + value copies (never `this`) so the thread can safely outlive us.
     auto bridge = bridge_;
@@ -340,14 +349,18 @@ bool LiteWalletController::beginOpenExisting()
         outcome.error = "could not reach any lite server";
         for (const auto& url : servers) {
             if (!bridge) break;
+            liteLog("  connecting to " + url + " ...");
             // initialize_existing loads the wallet file but contacts the server to start the
             // light client; ok && non-empty value == ready (mirrors the lifecycle's success test).
             const auto call = bridge->initializeExisting(/*dangerous=*/false, url);
             if (call.ok && !call.value.empty()) {
+                liteLog("  " + url + ": connected");
                 outcome.ok = true;
                 outcome.serverUrl = url;
                 break;
             }
+            const std::string why = call.error.empty() ? "unreachable" : call.error;
+            liteLog("  " + url + ": " + why);
             if (!call.error.empty()) outcome.error = call.error;
         }
         {
@@ -374,12 +387,14 @@ void LiteWalletController::pumpAsyncOpen()
         walletOpen_ = true;
         lastOpenError_.clear();
         status_ = WalletBackendStatus{WalletBackendState::Ready, "wallet open", {}, {}, 0.0};
+        liteLog("Wallet opened via " + outcome.serverUrl);
         if (persist_) persist_();
         startSync();    // begin background sync on the backend
         startWorker();  // begin periodic refresh -> WalletState
     } else {
         lastOpenError_ = outcome.error;
         status_ = WalletBackendStatus{WalletBackendState::Error, outcome.error, {}, {}, 0.0};
+        liteLog("Open failed: " + outcome.error);
     }
 }
 
@@ -387,6 +402,7 @@ void LiteWalletController::startSync()
 {
     if (syncLaunched_.exchange(true)) return;
     syncStarted_ = true;
+    liteLog("Background sync started");
     // The backend `sync` command is a blocking, uninterruptible full chain scan, so run it on
     // a detached thread. Capture shared refs (not the controller) so it is safe to outlive us.
     auto bridge = bridge_;

src/wallet/wallet_capabilities.h

@@ -43,7 +43,8 @@ enum class WalletUiSurface {
     BootstrapDownload,
     SetupWizard,
     NodeSettings,
-    LiteNetwork   // lite-wallet-only server browser (replaces Peers in lite builds)
+    LiteNetwork,  // lite-wallet-only server browser (replaces Peers in lite builds)
+    LiteConsole   // lite-wallet-only diagnostics console (full-node uses the RPC Console)
 };
 
 struct WalletCapabilities {
@@ -155,6 +156,7 @@ constexpr bool isUiSurfaceAvailable(const WalletCapabilities& capabilities,
         case WalletUiSurface::Explorer:
             return capabilities.fullNodePagesAvailable;
         case WalletUiSurface::LiteNetwork:
+        case WalletUiSurface::LiteConsole:
             return !capabilities.fullNodePagesAvailable;  // lite builds only
         case WalletUiSurface::BootstrapDownload:
         case WalletUiSurface::SetupWizard:

tests/test_phase4.cpp

@@ -25,6 +25,7 @@
 #include "util/xmrig_updater.h"
 #include "util/lite_server_probe.h"
 #include "wallet/lite_connection_service.h"
+#include "wallet/lite_diagnostics.h"
 #include "wallet/lite_owned_string.h"
 #include "wallet/lite_rollout_policy.h"
 #include "wallet/lite_wallet_controller.h"
@@ -3560,6 +3561,7 @@ void testLiteWalletControllerOpenFailover()
         dragonx::test::resetLiteFakeCounters();
         dragonx::test::g_liteFakeWalletExists = true;
         dragonx::test::g_liteFakeDeadServerSubstr = "dead.example";
+        LiteDiagnostics::instance().clear();  // verify the open populates the console log
         LiteWalletController controller(liteCaps, conn,
                                         LiteClientBridge::fromApi(dragonx::test::makeFakeLiteApi()));
         EXPECT_TRUE(controller.beginOpenExisting());
@@ -3569,6 +3571,17 @@ void testLiteWalletControllerOpenFailover()
         controller.pumpAsyncOpen();
         EXPECT_TRUE(controller.walletOpen());
         EXPECT_TRUE(controller.lastOpenError().empty());
+
+        // The Console tab reads this log: the failover attempt + success must be recorded.
+        const auto log = LiteDiagnostics::instance().snapshot();
+        EXPECT_TRUE(!log.empty());
+        bool sawConnecting = false, sawOpened = false;
+        for (const auto& l : log) {
+            if (l.find("connecting to") != std::string::npos) sawConnecting = true;
+            if (l.find("Wallet opened via") != std::string::npos) sawOpened = true;
+        }
+        EXPECT_TRUE(sawConnecting);
+        EXPECT_TRUE(sawOpened);
     }
 
     // All servers dead -> open fails, wallet stays closed, reason surfaced.