Fix Windows player: kiosk lockdown, robust video transitions, keep-awake

- Production/kiosk mode: exit_on_escape=0, window-close guard, Ctrl+C
  ignore, Alt+F4/Alt+Tab/Win/Ctrl+Esc keyboard hook (Windows)
- Robust video playback: async (non-blocking) ffpyplayer teardown,
  video progress watchdog (advance at true clip end), EOS re-entrancy
  guard, stale-advance guard, focus keeper for foreground retention
- Resume playback timer after Settings/exit popups close
- Windows keep-awake: SetThreadExecutionState + disable screensaver/
  lock screen (restored on exit)
- Always-on playback_trace.log for diagnosing transitions
- exe metadata: app_icon.ico + version_info.txt (publisher identity)

src/signage_player.kv

@@ -598,15 +598,26 @@
                         font_size: sp(12)
                         on_press: root.restart_player()
                 
-                # Test Connection Button
-                Button:
-                    id: test_connection_btn
-                    text: 'Test Server Connection'
+                # Test Connection + Production Mode Buttons
+                BoxLayout:
+                    orientation: 'horizontal'
                     size_hint_y: None
                     height: dp(44)
-                    background_color: 0.2, 0.4, 0.8, 1
-                    font_size: sp(13)
-                    on_press: root.test_connection()
+                    spacing: dp(8)
+
+                    Button:
+                        id: test_connection_btn
+                        text: 'Test Server Connection'
+                        background_color: 0.2, 0.4, 0.8, 1
+                        font_size: sp(13)
+                        on_press: root.test_connection()
+
+                    Button:
+                        id: production_mode_btn
+                        text: 'Enable Production'
+                        background_color: 0.4, 0.4, 0.4, 1  # grey = disabled
+                        font_size: sp(13)
+                        on_press: root.toggle_production_mode()
                 
                 # Connection Status Label
                 Label: