feat: re-instrument per STUB rules - all silent placeholders now panic

- PE-E03 pe_loader.c: unsupported base-reloc type silently skipped -> panic
- PE-E04 pe_shim.c ReadFile: fake TRUE+0-bytes ("pretend EOF") -> panic
- PE-E05 pe_shim.c CreateFileA: no file backend -> panic (no honest-failure excuse)
- PE-E06/E07 x86emu32.c: emu IAT unimplemented API / shim index OOB -> panic
- NETST-E01 net.c: netdev stats all-zero placeholder ("lying zero traffic") -> panic
- apic.c comment: SIPI reserved now points to DKM-E03 skeleton
- pe_dll_manager comments: circular-dep stub call now documented as PE-E01
- virtio_blk.c: capacity declaration marked as instrumentation whitelist
- QEMU verify: wizard -> Save -> verify ok -> login success -> desktop ready,
  zero spurious panics

[STUB] P1/UTSM/pe+net re-instrument sweep | 剩余STUB命中=101 (全部为 panic 坐标注释 /
IDT halt-stub 防御术语 / 白名单) | “未成之物，不留活口”

CODE/UTSM/kernel/net.c

@@ -1,5 +1,6 @@
 #include <utsm/net.h>
 #include <utsm/log.h>
+#include <utsm/panic.h>
 
 /*
  * 最小 netdev 注册表：
@@ -92,14 +93,15 @@ static int net_is_wireless_impl(u32 index) {
 }
 
 /* 统计查询：返回驱动层累计的收发统计。
- * 当前实现为占位：返回全零统计。
- * 后续由驱动在 tx/rx 回调内更新共享统计区，此处直接读取。
- * 驱动层的本地统计（如 e1000 的 g_stat_tx_ok 等）与 netdev 层统计
- * 通过 driver_ctx 统一后即可返回精确值。 */
+ * 严格错误策略插桩：全零统计占位 = 向上层谎报"网卡零流量"，
+ * 零降级 panic（NETST-E01）。驱动层统计区接入（driver_ctx 共享统计）
+ * 后才能提供真实语义。 */
 static int net_device_stats_impl(u32 index, dkm_net_stats *out) {
     if (!out) return -1;
     if (index >= g_net_device_count) return -2;
-    /* 占位：全零。后续由驱动填充实际统计。 */
+    (void)index;
+    panic_full("NETST-E01 NET STATS NOT IMPLEMENTED",
+               "netdev stats placeholder returns all-zero: driver stats wiring not implemented", 0);
     for (u32 i = 0; i < sizeof(dkm_net_stats); i++)
         ((u8 *)out)[i] = 0;
     return 0;