FX GUI embed: WS_EX_TOOLWINDOW + no minimize box for offscreen window (no stray taskbar button that cannot be restored)

native_bridge/src/RenderFxJob.cpp

@@ -961,6 +961,11 @@ static int fxGuiSetup(const std::string& jobPath, Vst3Fx* fx, HWND* hwndOut,
 
     // 3. Host window. Embedded mode parks it far off-screen (never steals
     //    focus; still visible to GDI so BitBlt captures real pixels).
+    //    WS_EX_TOOLWINDOW: an off-screen visible window would otherwise sit in
+    //    the taskbar; clicking its button "restores" it to -20000,-20000 and it
+    //    looks minimized/unrestorable. Tool window has no taskbar button.
+    //    WS_MINIMIZEBOX is dropped too (a minimized tool window is hard to get
+    //    back while parked off-screen).
     WNDCLASSA wc = {};
     wc.lpfnWndProc = FxGuiWndProc;
     wc.hInstance = GetModuleHandleA(nullptr);
@@ -968,9 +973,12 @@ static int fxGuiSetup(const std::string& jobPath, Vst3Fx* fx, HWND* hwndOut,
     RegisterClassA(&wc);
     const int x = offscreen ? -20000 : CW_USEDEFAULT;
     const int y = offscreen ? -20000 : CW_USEDEFAULT;
-    HWND hwnd = CreateWindowExA(0, kFxGuiWndClass,
+    const DWORD exStyle = offscreen ? WS_EX_TOOLWINDOW : 0;
+    const DWORD style = (offscreen ? (WS_OVERLAPPEDWINDOW & ~WS_MINIMIZEBOX) : WS_OVERLAPPEDWINDOW)
+                        | WS_VISIBLE | WS_CLIPCHILDREN | WS_CLIPSIBLINGS;
+    HWND hwnd = CreateWindowExA(exStyle, kFxGuiWndClass,
                                 (name.empty() ? "VST FX" : name).c_str(),
-                                WS_OVERLAPPEDWINDOW | WS_VISIBLE | WS_CLIPCHILDREN | WS_CLIPSIBLINGS,
+                                style,
                                 x, y, 800, 600,
                                 nullptr, nullptr, GetModuleHandleA(nullptr), nullptr);
     if (!hwnd) { std::cerr << "[FxGui] create window failed" << std::endl; return 1; }