Fix power button screen toggle instantly turning back on

Power button events were setting any_activity before the power handler's
continue, causing the generic wake logic to immediately re-enable the screen.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tools/rg35xx-screen-monitor.py

@@ -198,8 +198,6 @@ def main():
                 if ev_type == EV_SYN:
                     continue
 
-                any_activity = True
-
                 # Power button handling (EV_KEY only)
                 if ev_type == EV_KEY and ev_code == KEY_POWER:
                     if ev_value == 1:  # press
@@ -220,6 +218,8 @@ def main():
                         # Between SHORT and LONG threshold: ignore (release before 3s)
                     continue
 
+                any_activity = True
+
         # Any input activity resets idle shutdown timer
         if any_activity:
             last_active_time = time.monotonic()