fix(fx-gui): /show resize window+plugin view theo rect panel (layout khớp ô embed) — giữ offscreen, không topmost; sync sidecar mới vào bundle _internal

native_bridge/src/FxGuiServer.cpp

@@ -514,11 +514,21 @@ void runHttpServer(HWND hwnd, std::atomic<bool>& stop) {
             if (sroot) std::free(sroot);
             // Embedded mode: the native window NEVER comes on-screen — it stays
             // parked off-screen at -20000,-20000 (GDI capture + synthetic input
-            // work regardless of position). The panel rect is still recorded
-            // for the (disabled) real-input fallback and to keep the API
-            // contract; /hide hid the window, so re-show it off-screen so
+            // work regardless of position). The panel rect sizes the host
+            // window + plugin view so the capture frame matches the embed panel
+            // (layout bug); /hide hid the window, so re-show it off-screen so
             // /frame keeps capturing.
-            (void)rectOk;
+            if (rectOk) {
+                const int cw = g_embedRect.right - g_embedRect.left;
+                const int ch = g_embedRect.bottom - g_embedRect.top;
+                RECT cur = {};
+                GetWindowRect(hwnd, &cur);
+                // Skip when already the right size: frontend re-POSTs /show
+                // every ~500ms; re-laying-out the plugin view every tick is
+                // wasteful (WM_FXGUI_RESIZE -> checkSizeConstraint/onSize).
+                if (cur.right - cur.left != cw || cur.bottom - cur.top != ch)
+                    fxGuiRequestResize(hwnd, cw, ch);
+            }
             if (!IsWindowVisible(hwnd))
                 SetWindowPos(hwnd, HWND_NOTOPMOST, -20000, -20000, 0, 0,
                              SWP_NOSIZE | SWP_NOACTIVATE | SWP_SHOWWINDOW);