chore: remove unused config_screen UI stubs

Remove the ui/ directory containing config_screen stubs that were
left over from the display removal. This code was not compiled
(not listed in CMakeLists.txt) and had no callers.

Signed-off-by: Asklv <boironic@gmail.com>

main/ui/config_screen.c

@@ -1,29 +0,0 @@
-#include "ui/config_screen.h"
-
-#include "esp_log.h"
-
-static const char *TAG = "config_screen";
-static bool s_active = false;
-
-void config_screen_init(void)
-{
-    s_active = false;
-}
-
-void config_screen_toggle(void)
-{
-    s_active = !s_active;
-    ESP_LOGI(TAG, "Config screen is disabled (active=%s)", s_active ? "true" : "false");
-}
-
-bool config_screen_is_active(void)
-{
-    return s_active;
-}
-
-void config_screen_scroll_down(void)
-{
-    if (s_active) {
-        ESP_LOGI(TAG, "Config screen scrolling is disabled");
-    }
-}

main/ui/config_screen.h

@@ -1,8 +0,0 @@
-#pragma once
-
-#include <stdbool.h>
-
-void config_screen_init(void);
-void config_screen_toggle(void);
-bool config_screen_is_active(void);
-void config_screen_scroll_down(void);