refactor(app): App-per-screen navigation, remove menu_level entirely

Splits the ad-hoc menu_level state machine into standalone Apps with a
uniform parent/child exit convention (long-press CONFIRM -> parent):
clock_app renamed to home_app (boot-default), new set_clock_app
extracted from home_app's time-edit mode, new ipc_bind_app extracted
from menu_app's old level-2 screen, and the sensor-type selection step
merged into pair_app as its new initial state. menu_app now only holds
the 4-item top-level list (language toggle inline). Also makes both
menu_app and pair_app's up/down navigation cyclic (wraps at both ends).

App/app_set_clock.c

@@ -0,0 +1,133 @@
+#include "app_manager.h"
+#include "clock.h"
+#include "xtell.h"
+#include "ui.h"
+#include "rgb.h"
+#include "event.h"
+#include "system.h"
+#include "../Drivers/pcf8563.h"
+
+// 外部引用的全局系统状态变量
+extern SystemState current_state;
+extern volatile u16 ms_tick;
+
+// 本应用私有的时间编辑状态
+static u8 time_edit_field = 1;    // 标识当前聚焦在哪一个参数上进行微调 (1:修改小时, 2:修改分钟)
+static u8 time_edit_blink_on = 1; // 时钟修改时光标闪烁周期状态位
+
+// 声明本应用的生命周期回调函数
+static void SetClockApp_OnStart(void);
+static void SetClockApp_onRun(void);
+static void SetClockApp_onClose(void);
+static EventResult SetClockApp_onEvent(SystemEvent *evt);
+
+// 实体化定义时间设置应用控制块 (从 menu_app 的"HORLOGE"选项进入)
+WristbandApp set_clock_app = {
+    APP_ID_SET_CLOCK,
+    "SetClock",
+    SetClockApp_OnStart,
+    SetClockApp_onRun,
+    SetClockApp_onClose,
+    SetClockApp_onEvent
+};
+
+/**
+ * @brief SetClockApp 启动回调
+ */
+static void SetClockApp_OnStart(void)
+{
+    time_edit_field = 1;
+    time_edit_blink_on = 1;
+    current_state = STATE_SET_TIME; // 系统切入时间设置状态
+
+    // FCOB 幻彩灯条双灯珠均显示蓝色常亮 (R=0, G=0, B=180)，进行模式视觉区分
+    RGB_Send(0, 0, 180, 0, 0, 180);
+
+    // 振动马达单次短震 50 毫秒，提供触觉反馈
+    MOTOR = 1;
+    Delay_ms(50);
+    MOTOR = 0;
+
+    // 渲染显示时间编辑界面，默认高亮编辑小时字段，消隐位开启
+    UI_ShowSetTimePage(current_hour, current_min, time_edit_field, 1);
+    XTELL_LOG("[SetClockApp] Started\r\n");
+}
+
+/**
+ * @brief SetClockApp 轮询主回调
+ */
+static void SetClockApp_onRun(void)
+{
+    // ====== 时间设置闪烁动画 (周期 500ms) ======
+    u8 blink = (ms_tick / 500) % 2;
+    if (blink != time_edit_blink_on)
+    {
+        time_edit_blink_on = blink;
+        // 每次闪烁状态发生变化，重新刷写屏幕数值
+        UI_ShowSetTimePage(current_hour, current_min, time_edit_field, time_edit_blink_on);
+    }
+}
+
+/**
+ * @brief SetClockApp 退出清理回调
+ */
+static void SetClockApp_onClose(void)
+{
+    RGB_Send(0, 0, 0, 0, 0, 0); // 关闭灯条
+    XTELL_LOG("[SetClockApp] Closed\r\n");
+}
+
+/**
+ * @brief SetClockApp 接收按键事件处理回调
+ */
+static EventResult SetClockApp_onEvent(SystemEvent *evt)
+{
+    if (evt->key_event == KEY_EVENT_UP_CLICK)
+    {
+        // 短按 ▲ 键增加数值 (小时/分钟循环相加)
+        if (time_edit_field == 1) {
+            current_hour = (current_hour + 1) % 24;
+        } else {
+            current_min = (current_min + 1) % 60;
+        }
+        UI_ShowSetTimePage(current_hour, current_min, time_edit_field, 1);
+        return EVENT_HANDLED;
+    }
+    if (evt->key_event == KEY_EVENT_DOWN_CLICK)
+    {
+        // 短按 ▼ 键减小数值
+        if (time_edit_field == 1) {
+            current_hour = (current_hour == 0) ? 23 : (current_hour - 1);
+        } else {
+            current_min = (current_min == 0) ? 59 : (current_min - 1);
+        }
+        UI_ShowSetTimePage(current_hour, current_min, time_edit_field, 1);
+        return EVENT_HANDLED;
+    }
+    if (evt->key_event == KEY_EVENT_CONFIRM_LONG)
+    {
+        // 长按 ■ 确认键切换调节字段 (在修改小时与修改分钟间跳转)
+        if (time_edit_field == 1) {
+            time_edit_field = 2;
+        } else {
+            time_edit_field = 1;
+        }
+        UI_ShowSetTimePage(current_hour, current_min, time_edit_field, 1);
+        return EVENT_HANDLED;
+    }
+    if (evt->key_event == KEY_EVENT_CONFIRM_CLICK)
+    {
+        // 短按 ■ 确认键保存最新时钟配置，退出到主菜单 (父 App)
+        current_state = STATE_PAIR_MENU;
+
+        // 同步将最新时间 (hour, min, 0秒) 写入 PCF8563 芯片寄存器
+        PCF8563_WriteTime(current_hour, current_min, 0);
+
+        // 退出短振反馈
+        MOTOR = 1; Delay_ms(50); MOTOR = 0;
+
+        AppManager_SwitchToForeground(&menu_app);
+        return EVENT_HANDLED;
+    }
+    return EVENT_HANDLED; // 在时间设置模式下屏蔽拦截其他一切无关按键事件
+}