feat: screenshot app improvement, WIndow Server supports full-screen overlay, Disks app UI improvements

programs/include/gui/standalone.hpp

@@ -70,6 +70,11 @@ struct WsWindow {
             montauk::win_setcursor(id, cursor);
     }
 
+    void set_flags(uint32_t flags) const {
+        if (id >= 0)
+            montauk::win_setflags(id, flags);
+    }
+
     void destroy() {
         if (id >= 0)
             montauk::win_destroy(id);

programs/include/gui/window.hpp

@@ -67,6 +67,7 @@ struct Window {
     bool external;      // true = shared-memory window from external process
     int  ext_win_id;    // window server ID (valid when external == true)
     uint8_t ext_cursor; // cursor style requested by external app (0=arrow, 1=resize_h, 2=resize_v)
+    uint32_t ext_flags;
 
     Rect titlebar_rect() const {
         return {frame.x, frame.y, frame.w, TITLEBAR_HEIGHT};