feat(ui): keep the wallet syncing while minimized

Previously the main loop just did SDL_Delay+continue when minimized, skipping app.update() —
so the wallet stopped draining RPC results, ticking the refresh scheduler, and reconnecting
until it was restored (and a large daemon-output backlog piled up, which is what produced the
spurious "rescan complete" toast on restore).

Now app.update() runs while minimized (it only reads GetIO/GetTime/IsAnyItemActive, all valid
outside a NewFrame) with a real-clock DeltaTime, skipping only the ImGui frame + GPU present,
throttled to ~5 Hz so CPU stays near-idle. Also clamp io.DeltaTime at the top of App::update()
so a long minimize (or machine sleep) can't report a huge delta and fire every refresh/animation
timer at once on the next update. No backlog now builds, so skipDaemonOutputBacklog becomes a
harmless no-op.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/app.cpp

@@ -739,6 +739,10 @@ void App::update()
 {
     PERF_SCOPE("Update.Total");
     ImGuiIO& io = ImGui::GetIO();
+    // Clamp the frame delta: after a long pause (window minimized, or the machine slept) NewFrame reports
+    // a huge DeltaTime that would fire every refresh/animation timer at once. Every timer reads
+    // io.DeltaTime, so one clamp here bounds them all (also caps the real-clock delta fed while minimized).
+    if (io.DeltaTime > 0.25f) io.DeltaTime = 0.25f;
 
     // Full UI screenshot sweep: demo state is injected once and must stay frozen. Skip every live
     // op (refresh/connect/pumps) so a real daemon can't clobber it — on Windows a running node's

src/main.cpp

@@ -1500,6 +1500,7 @@ int main(int argc, char* argv[])
     // WINDOW_RESIZED events during the transition can't corrupt savedSizeForScale / lastKnownW/H.
     int dpiSettleFrames = 0;
     SDL_DisplayID lastLoggedDisplay = 0;   // [WINLOG] throttle: log MOVED only when the display changes
+    Uint64 minimizedLastTickMs = 0;        // real-clock tick for the minimized "keep syncing" update
     {
         float s = dragonx::ui::material::Typography::instance().getDpiScale();
         int w = 0, h = 0;
@@ -1734,13 +1735,28 @@ int main(int argc, char* argv[])
 
         // Check if window is minimized
         if (SDL_GetWindowFlags(window) & SDL_WINDOW_MINIMIZED) {
-            // Still check shouldQuit while minimized to avoid hang
-            if (app.shouldQuit()) {
-                running = false;
-            }
-            SDL_Delay(10);
+            // Keep the wallet syncing while minimized: run the logic update (drains RPC results, ticks the
+            // refresh scheduler, keeps the daemon connection/reconnect + sync status live) but skip the
+            // ImGui frame + GPU present since nothing is visible. app.update() only reads
+            // GetIO()/GetTime()/IsAnyItemActive() — all valid outside a frame — so it's safe without a
+            // NewFrame; feed it a real-clock DeltaTime (NewFrame, which normally sets it, is skipped) and
+            // let app.update() clamp it. Throttled to ~5 Hz so CPU stays near-idle (refresh cadences are
+            // seconds-scale). shouldQuit is still checked so a quit request never hangs behind minimize.
+            Uint64 nowMs = SDL_GetTicks();
+            float minDelta = (minimizedLastTickMs == 0) ? 0.001f
+                                                        : (float)(nowMs - minimizedLastTickMs) / 1000.0f;
+            minimizedLastTickMs = nowMs;
+            ImGui::GetIO().DeltaTime = (minDelta > 0.0f) ? minDelta : 0.001f;
+            try {
+                app.update();
+            } catch (const std::exception& e) {
+                DEBUG_LOGF("[Main] minimized app.update() threw: %s\n", e.what());
+            } catch (...) {}
+            if (app.shouldQuit()) running = false;
+            SDL_Delay(200);
             continue;
         }
+        minimizedLastTickMs = 0;   // visible again — reset the minimized clock
 
         // --- PerfLog: begin frame ---
         dragonx::util::PerfLog::instance().beginFrame();