feat: WiFi驱动(ath9k) + TTF字体 + shell命令行 + FirstInit WiFi跳过

新增: ath9k PCIe WiFi驱动(被动扫描/beacon解析), shell命令行(help/clear/echo/version/date/reboot/halt), Consolas 18px TTF字体, render_ascii.py

修改: dkm_net_api扩展scan接口, FirstInit无WiFi设备时跳过, DSK加载shell.elf, 非首次启动直接进shell

CODE/UTSM/kernel/net.c

@@ -5,6 +5,9 @@
  * 最小 netdev 注册表：
  * - 早期 DKM 驱动加载路径是单线程顺序执行，当前无需引入锁，避免在网络底座阶段扩大复杂度。
  * - 后续进入多核/热插拔后，应在 register/device_info 外围加自旋锁或 RCU 风格只读快照。
+ *
+ * 无线扫描接口（scan_start/scan_count/scan_result/is_wireless）通过 dispatch 转发到驱动
+ * 注册的回调。有线驱动（e1000/virtio_net）不填这些回调，dispatch 时返回 -3 表示不支持。
  */
 static dkm_net_device_desc g_net_devices[DKM_NET_MAX_DEVICES];
 static u32 g_net_device_count;
@@ -60,12 +63,45 @@ static int net_rx_poll_impl(u32 index, void *buffer, u32 capacity, u32 *out_leng
     return dev->rx_poll(dev->ctx, buffer, capacity, out_length);
 }
 
+static int net_scan_start_impl(u32 index) {
+    if (index >= g_net_device_count) return -2;
+    const dkm_net_device_desc *dev = &g_net_devices[index];
+    if (!dev->scan_start) return -3;
+    return dev->scan_start(dev->ctx);
+}
+
+static int net_scan_count_impl(u32 index) {
+    if (index >= g_net_device_count) return -2;
+    const dkm_net_device_desc *dev = &g_net_devices[index];
+    if (!dev->scan_count) return -3;
+    return dev->scan_count(dev->ctx);
+}
+
+static int net_scan_result_impl(u32 index, u32 n, dkm_net_scan_result *out) {
+    if (!out) return -1;
+    if (index >= g_net_device_count) return -2;
+    const dkm_net_device_desc *dev = &g_net_devices[index];
+    if (!dev->scan_result) return -3;
+    return dev->scan_result(dev->ctx, n, out);
+}
+
+static int net_is_wireless_impl(u32 index) {
+    if (index >= g_net_device_count) return -2;
+    const dkm_net_device_desc *dev = &g_net_devices[index];
+    if (dev->is_wireless) return dev->is_wireless(dev->ctx);
+    return (dev->flags & DKM_NET_F_WIRELESS) ? 1 : 0;
+}
+
 static const dkm_net_api g_net_api = {
     .register_device = net_register_device_impl,
     .device_count = net_device_count_impl,
     .device_info = net_device_info_impl,
     .tx = net_tx_impl,
-    .rx_poll = net_rx_poll_impl
+    .rx_poll = net_rx_poll_impl,
+    .scan_start = net_scan_start_impl,
+    .scan_count = net_scan_count_impl,
+    .scan_result = net_scan_result_impl,
+    .is_wireless = net_is_wireless_impl
 };
 
 const dkm_net_api *net_get_api(void) {