feat(panel): 锁屏一次性解锁端点 POST /api/system/pin-unlock-once（写 /tmp/meow_pin_unlock_once，launcher 锁屏页消费放行一次）+ 设置页 PIN 卡「一次性解锁设备」按钮

patch_v2/meowpanel/meowpanel.c

@@ -3493,6 +3493,17 @@ static int api_system(int sock)
     return ret;
 }
 
+/* ---------------- 锁屏一次性解锁（写 /tmp/meow_pin_unlock_once，launcher 锁屏页消费） ---------------- */
+static int api_pin_unlock_once(int sock)
+{
+    const char *path = "/tmp/meow_pin_unlock_once";
+    FILE *f = fopen(path, "w");
+    if (!f) return send_err(sock, 500, "INTERNAL", "无法写入一次性解锁标志");
+    fputs("1\n", f);
+    fclose(f);
+    return send_json(sock, 200, "{\"unlock_once\":true}");
+}
+
 /* ---------------- 系统动作（经 meow_svc_power IPC） ---------------- */
 static int api_system_action(int sock, const char *which, const req_t *r)
 {
@@ -5397,6 +5408,7 @@ static int handle(int sock, req_t *r)
         if (!strcmp(p, "/api/system/reboot")) return api_system_action(sock, "reboot", r);
         if (!strcmp(p, "/api/system/shutdown")) return api_system_action(sock, "shutdown", r);
         if (!strcmp(p, "/api/system/ota")) return api_system_action(sock, "ota", r);
+        if (!strcmp(p, "/api/system/pin-unlock-once")) return api_pin_unlock_once(sock);
         if (!strcmp(p, "/api/settings")) return api_settings_batch(sock, r);
         if (!strcmp(p, "/api/settings/restore")) return api_settings_restore(sock);
         if (!strcmp(p, "/api/theme")) return api_theme_put(sock, r);