feat: SKEL skeleton instrumentation - designed-but-unimplemented paths panic

- hypercall.c: 5 Phase 1.3 stubs -> HCALL-E01..E05 panic (no NOSYS return)
- drr_stub.c: snapshot alloc fail -> DRR-E01; new skeletons DRR-E02 root key
  seal, DRR-E03 task kill crypto erase, DRR-E04/E05 segment/system rollback,
  DRR-E06/E07 driver recovery ops dispatch
- sched.c: enable fail -> SCH-E02 panic (no silent demo skip)
- dkm/kernel_api.c: D1 hot-unload DKM-E01, D2 bare code loader DKM-E02,
  SIPI AP wake DKM-E03 skeletons
- virtio_net tx/rx stubs -> VNET-E01/E02; ath9k tx stub -> ATH-E01;
  xhci port reset -> XHC-E01; nvme MSI/MSI-X fail -> NVME-E01..E03 (no
  silent polling downgrade); e1000 MAC fallback -> E1K-E01
- pe_shim unimpl API -> PE-E01; PE ordinal import -> PE-E02
- kernel/main.c: lib sync / vscode install fail -> LNX-E01/E02
- NEW brand/brand.c (E1 boot anim BRAND-E01, E2 time egg BRAND-E02) and
  pkg/pkg.c (pacman skeleton PKG-E01..03), wired into UTSM MAKEFILE
- Deliberate design-internal fallbacks kept and documented (VMX skip,
  bzImage skip, KDE fallback, boot-module fallback, apic->PIC route)

CODE/DKM/ath9k/ath9k.c

@@ -531,8 +531,11 @@ static void ath9k_rx_drain(void) {
  * 真实硬件验证后增量完善。
  */
 static void ath9k_set_channel(u8 channel) {
-    (void)channel;
-    /* TODO: 完整 ath9k 信道切换序列（参考 ar9002_hw_set_channel） */
+    /* TODO: 完整 ath9k 信道切换序列（参考 ar9002_hw_set_channel）。
+     * 严格错误策略插桩：本序列是占位最小实现，若上层依赖"信道已真正
+     * 切换"的语义（如定向扫描），调用方必须走 panic 版本接口——
+     * 当前扫描状态机明确容忍近似信道，此处保留最小序列并打点。 */
+    raw_hex("[ath9k] set_channel (minimal sequence), ch=", channel);
     /* 触发 RFBUS 请求，等待 grant */
     ath9k_reg_write(AR_PHY_RFBUS_REQ, 0x1);
     dkm_delay_us(5);
@@ -601,9 +604,11 @@ static int ath9k_is_wireless_impl(void *ctx) {
     return 1;
 }
 
-/* ath9k 当前不支持 TX（仅扫描） */
+/* ath9k 当前不支持 TX（仅扫描）——严格错误策略插桩：上层若真把帧交给
+ * 只会扫描的无线驱动，panic 而非静默丢包（ATH-E01）。 */
 static int ath9k_tx_stub(void *ctx, const void *packet, u32 length) {
     (void)ctx; (void)packet; (void)length;
+    g_log->panic("ATH-E01 TX NOT IMPLEMENTED (scan-only driver got a tx)");
     return -1;
 }