text fields: button state in motion events + i-beam cursor

- Track current_buttons bitmask on press/release
- Set u.motion.state = current_mods | current_buttons so WINGs
  text fields see WM_BUTTON1_MASK during click-drag selection
- Implement wl_set_cursor via W_SetCursorImageFn hook for i-beam

src/backend/wayland/wl_handlers.c

@@ -258,7 +258,13 @@ handle_pointer_button(struct wl_listener *listener, void *data)
         case 0x112: wev.u.button.button = 2; break;
         default:    wev.u.button.button = (ev->button - 0x110) + 1; break;
         }
-        wev.u.button.state = wl_state.current_mods;
+        /* Track button mask for motion events (WM_BUTTON*_MASK = 0x100<<n) */
+        unsigned int bmask = (1u << 8) << (wev.u.button.button - 1);
+        if (ev->state == WLR_BUTTON_PRESSED)
+            wl_state.current_buttons |= bmask;
+        else
+            wl_state.current_buttons &= ~bmask;
+        wev.u.button.state = wl_state.current_mods | wl_state.current_buttons;
         /* For WINGs views, resolve the child widget at click coordinates.
          * Two cases:
          * 1. fb->id >= 0x20000000 — fb IS a WINGs view frame_buf, use directly.

src/backend/wayland/wl_pointer_motion.c

@@ -90,6 +90,7 @@ handle_pointer_motion(struct wl_listener *listener, void *data)
         wev.u.motion.time   = ev->time_msec;
         wev.u.motion.x_root = wl_state.pointer_x;
         wev.u.motion.y_root = wl_state.pointer_y;
+        wev.u.motion.state  = wl_state.current_mods | wl_state.current_buttons;
         /* Resolve WINGs child view (slider, etc.) at pointer for
          * motion routing during drag operations. */
         struct W_View *mtarget = NULL;
@@ -214,6 +215,7 @@ handle_pointer_motion_absolute(struct wl_listener *listener, void *data)
         wev.u.motion.time   = ev->time_msec;
         wev.u.motion.x_root = wl_state.pointer_x;
         wev.u.motion.y_root = wl_state.pointer_y;
+        wev.u.motion.state  = wl_state.current_mods | wl_state.current_buttons;
         W_WL_EnqueueEvent(wmscr2, &wev, NULL);
         /* Emit synthetic LEAVE/ENTER on sub-window boundary crossings. */
         if (new_id != wl_state.last_hovered_id) {

src/backend/wayland/wl_types.h

@@ -412,6 +412,7 @@ struct wl_compositor_state {
      * handle_keyboard_modifiers.  Used by handle_pointer_button to populate
      * u.button.state so frameMouseDown can detect Alt/Super+drag. */
     unsigned int                     current_mods;
+    unsigned int                     current_buttons; /* WM_BUTTON*_MASK bits */
 };
 
 extern struct wl_compositor_state wl_state;