V45.38: suppress iZotope 0x7E dialog

- _is_vst2_dll: pure-Python PE export-table check (magic-aware dd offset
  PE32+112) -> IZOzone11Core.dll (runtime lib, no VSTPluginMain) dropped
  from VST2 lists in _scan_plugins and list_scan_all; plugins.py same.
- _hidden_desktop_startupinfo: scan subprocess runs on hidden desktop
  (user32 CreateDesktopW, HDESK restype) -> third-party MessageBox invisible.
- SetErrorMode(SEM_FAILCRITICALERRORS|SEM_NOOPENFILEERRORBOX) in all 4
  bridge mains: missing dependency DLL fails silently instead of blocking.

native_bridge/src/gui_probe.cpp

@@ -106,6 +106,10 @@ public:
 };
 
 int main(int argc, char* argv[]) {
+#ifdef _WIN32
+    // Suppress Windows loader error dialogs (0x7E) during probe loads.
+    SetErrorMode(SEM_FAILCRITICALERRORS | SEM_NOOPENFILEERRORBOX);
+#endif
     if (argc < 2) {
         printf("usage: gui_probe <plugin.vst3> [variant] [secs] [hwnd]\n"
                "variants: main_own | worker_own_nopump | worker_own_pump | worker_foreign_nopump | worker_foreign_pump | bridge_like | same_thread | two_instances | two_instances_close | close_reopen | bridge_two | shared_worker | ui_thread | two_workers_close\n");