v1.2.0: UX audit — security fixes, accessibility, and polish

Security (P0):
- Fix sidebar remaining interactive behind lock screen
- Extend auto-lock idle detection to include active widget interactions
- Distinguish missing PIN vault from wrong PIN; auto-switch to passphrase

Blocking UX (P1):
- Add 15s timeout for encryption state check to prevent indefinite loading
- Show restart reason in loading overlay after wallet encryption
- Add Force Quit button on shutdown screen after 10s
- Warn user if embedded daemon fails to start during wizard completion

Polish (P2):
- Use configured explorer URL in Receive tab instead of hardcoded URL
- Increase request memo buffer from 256 to 512 bytes to match Send tab
- Extend notification duration to 5s for critical operations (tx sent,
  wallet encrypted, key import, backup, export)
- Add Reduce Motion accessibility setting (disables page fade + balance lerp)
- Show estimated remaining time during mining thread benchmark
- Add staleness indicator to market price data (warning after 5 min)

New i18n keys: incorrect_pin, incorrect_passphrase, pin_not_set,
restarting_after_encryption, force_quit, reduce_motion, tt_reduce_motion,
ago, wizard_daemon_start_failed

src/app.cpp

@@ -316,7 +316,8 @@ void App::update()
     // Track user interaction for auto-lock
     if (io.MouseDelta.x != 0 || io.MouseDelta.y != 0 ||
         io.MouseClicked[0] || io.MouseClicked[1] ||
-        io.InputQueueCharacters.Size > 0) {
+        io.InputQueueCharacters.Size > 0 ||
+        ImGui::IsAnyItemActive()) {
         last_interaction_ = std::chrono::steady_clock::now();
     }
 
@@ -1024,7 +1025,8 @@ void App::render()
     bool prevCollapsed = sidebar_collapsed_;
     {
         PERF_SCOPE("Render.Sidebar");
-        ui::RenderSidebar(current_page_, sidebarW, sidebarH, sbStatus, sidebar_collapsed_);
+        ui::RenderSidebar(current_page_, sidebarW, sidebarH, sbStatus, sidebar_collapsed_,
+                          state_.isLocked());
     }
     if (sbStatus.exitClicked) {
         requestQuit();
@@ -1039,7 +1041,7 @@ void App::render()
 
     // Page transition: detect change, ramp alpha
     if (current_page_ != prev_page_) {
-        page_alpha_ = ui::effects::isLowSpecMode() ? 1.0f : 0.0f;
+        page_alpha_ = (ui::effects::isLowSpecMode() || (settings_ && settings_->getReduceMotion())) ? 1.0f : 0.0f;
         prev_page_  = current_page_;
     }
     if (page_alpha_ < 1.0f) {
@@ -1094,6 +1096,18 @@ void App::render()
         // Lock screen — covers tab content just like the loading overlay
         renderLockScreen();
     } else if (pageNeedsDaemon && (!daemonReady || (state_.connected && !state_.encryption_state_known))) {
+        // Track how long we've been waiting for encryption state
+        if (state_.connected && !state_.encryption_state_known) {
+            encryption_check_timer_ += ImGui::GetIO().DeltaTime;
+            if (encryption_check_timer_ >= 15.0f) {
+                DEBUG_LOGF("[App] Encryption state check timed out after 15s — assuming unencrypted\n");
+                state_.encryption_state_known = true;
+                state_.encrypted = false;
+                encryption_check_timer_ = 0.0f;
+            }
+        } else {
+            encryption_check_timer_ = 0.0f;
+        }
         // Reset lock screen focus flag so it auto-focuses next time
         lock_screen_was_visible_ = false;
         // Show loading overlay instead of tab content
@@ -2403,11 +2417,14 @@ void App::renderShutdownScreen()
     ImGui::PushStyleColor(ImGuiCol_WindowBg, ImVec4(0.06f, 0.06f, 0.08f, 0.92f));
     ImGui::PushStyleVar(ImGuiStyleVar_WindowRounding, 0.0f);
     ImGui::PushStyleVar(ImGuiStyleVar_WindowBorderSize, 0.0f);
-    ImGui::Begin("##ShutdownOverlay", nullptr,
+    ImGuiWindowFlags shutdownFlags =
         ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoResize |
         ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoScrollbar |
-        ImGuiWindowFlags_NoInputs | ImGuiWindowFlags_NoNav |
-        ImGuiWindowFlags_NoSavedSettings);
+        ImGuiWindowFlags_NoSavedSettings;
+    // Allow input after 10s so Force Quit button is clickable
+    if (shutdown_timer_ < 10.0f)
+        shutdownFlags |= ImGuiWindowFlags_NoInputs | ImGuiWindowFlags_NoNav;
+    ImGui::Begin("##ShutdownOverlay", nullptr, shutdownFlags);
 
     ImDrawList* dl = ImGui::GetWindowDrawList();
     // Convert local centre to screen coords for draw-list primitives
@@ -2505,6 +2522,25 @@ void App::renderShutdownScreen()
         ImGui::PopFont();
     }
 
+    // -------------------------------------------------------------------
+    // 4b. Force Quit button — appears after 10 seconds
+    // -------------------------------------------------------------------
+    if (shutdown_timer_ >= 10.0f) {
+        ImGui::Spacing();
+        ImGui::Spacing();
+        const char* forceLabel = TR("force_quit");
+        ImVec2 btnSize(ImGui::CalcTextSize(forceLabel).x + 32.0f, 0);
+        ImGui::SetCursorPosX(cx - btnSize.x * 0.5f);
+        ImGui::PushStyleColor(ImGuiCol_Button, ImVec4(0.6f, 0.15f, 0.15f, 0.9f));
+        ImGui::PushStyleColor(ImGuiCol_ButtonHovered, ImVec4(0.75f, 0.2f, 0.2f, 1.0f));
+        ImGui::PushStyleColor(ImGuiCol_ButtonActive, ImVec4(0.5f, 0.1f, 0.1f, 1.0f));
+        if (ImGui::Button(forceLabel, btnSize)) {
+            DEBUG_LOGF("Force quit requested by user after %.0fs\n", shutdown_timer_);
+            shutdown_complete_ = true;
+        }
+        ImGui::PopStyleColor(3);
+    }
+
     ImGui::Spacing();
     ImGui::Spacing();