feat(panic): FUCK [panic] mode=strict|fallback + realtest image variant

- UTSM panic_full returns in fallback mode (logs [PANIC:FALLBACK] + code + hit
  count); panic_halt keeps always-halt sites (CPU exception, VMM-E11 LA57,
  VMM-E15 DSK jump, UTSM-E42 test hook). Call sites given safe continuations.
- Mode passed to DSK/FirstInit/login/desktop via DSK_BOOT_FLAG_PANIC_FALLBACK;
  DKM kernel_api.panic / kern.log.panic return to driver; ext4 fatal aborts the
  op via setjmp/longjmp and DSK falls back to FAT32 ESP.
- build.ps1/Makefile: dev=strict, release=fallback, new realtest (release
  options + strict); default -Variant all; serialized iso packing under -j.
- Fix '*/' inside comments (dkm.h, kernel_api.h, bus.c) that broke the build.
- Includes pending work: dkm_bus service bus, mt7920/wlan drivers, desktop
  files/startmenu/prank, pe-tools, diskinfo, docs.

Co-authored-by: Cursor <cursoragent@cursor.com>

CODE/tools/pe-tools/portio.cpp

@@ -0,0 +1,121 @@
+/* portio.cpp — Deshab 端口读写工具（控制台 PE64，diskpart 风格硬件调试）
+ *
+ * 用法（在 CMD 里运行，输出走串口）：
+ *   portio <port>            读一字节（十六进制端口）
+ *   portio <port> <value>    写一字节
+ *   portio                   用法帮助
+ *
+ * 例：
+ *   portio 70        → 读 CMOS 地址口
+ *   portio 70 0      → CMOS 寄存器 0（秒）
+ *   portio 71        → 读出秒（BCD）
+ *
+ * Ring0 原生执行，IOPL 无限制。危险提示：写错端口可能挂机。
+ */
+#include <windows.h>
+
+typedef unsigned int   u32;
+typedef unsigned char  u8;
+typedef unsigned short u16;
+
+static inline u8 inpb(u16 port) {
+    u8 v;
+    __asm__ volatile("inb %1,%0" : "=a"(v) : "Nd"(port));
+    return v;
+}
+static inline void outpb(u16 port, u8 v) {
+    __asm__ volatile("outb %0,%1" :: "a"(v), "Nd"(port));
+}
+
+static void ps(const char *s) { while (*s) putchar(*s++); }
+static void pch(char c) { putchar(c); }
+static void ph(u32 v) {
+    static const char hd[] = "0123456789ABCDEF";
+    ps("0x");
+    for (int i = 3; i >= 0; i--) pch(hd[(v >> (i * 4)) & 0xF]);
+}
+
+/* 解析十进制/0x 前缀十六进制；成功返回 0 */
+static int parse_num(const char *s, u32 *out) {
+    u32 v = 0;
+    if (!s || !s[0]) return -1;
+    if (s[0] == '0' && (s[1] == 'x' || s[1] == 'X')) {
+        s += 2;
+        if (!s[0]) return -1;
+        for (;;) {
+            char c = *s++;
+            if (!c) break;
+            int d;
+            if (c >= '0' && c <= '9') d = c - '0';
+            else if (c >= 'a' && c <= 'f') d = c - 'a' + 10;
+            else if (c >= 'A' && c <= 'F') d = c - 'A' + 10;
+            else return -1;
+            v = v * 16 + (u32)d;
+        }
+    } else {
+        for (;;) {
+            char c = *s++;
+            if (!c) break;
+            if (c < '0' || c > '9') return -1;
+            v = v * 10 + (u32)(c - '0');
+        }
+    }
+    *out = v;
+    return 0;
+}
+
+/* 从 cmdline 提取第 n 个空格分隔 token（0 = 程序名） */
+static int token(const char *cmd, int n, char *out, int cap) {
+    int idx = 0, ti = 0;
+    const char *p = cmd;
+    while (*p) {
+        while (*p == ' ') p++;
+        if (!*p) break;
+        ti = 0;
+        while (*p && *p != ' ') {
+            if (idx == n && ti < cap - 1) out[ti++] = *p;
+            p++;
+        }
+        if (idx == n) {
+            out[ti] = 0;
+            return ti > 0 ? 0 : -1;
+        }
+        idx++;
+    }
+    return -1;
+}
+
+int main(void) {
+    const char *cmd = GetCommandLineA();
+    char t1[32], t2[32];
+    u32 port, val;
+
+    if (token(cmd, 1, t1, sizeof(t1)) != 0) {
+        ps("Deshab portio - port read/write tool (serial console)\r\n");
+        ps("usage: portio <port> [value]   (hex with 0x, or decimal)\r\n");
+        ps("  portio 70        read CMOS address port\r\n");
+        ps("  portio 70 0      select CMOS reg 0 (seconds)\r\n");
+        ps("  portio 71        read seconds (BCD)\r\n");
+        ps("WARNING: wrong port writes can hang the machine.\r\n");
+        ExitProcess(0);
+    }
+    if (parse_num(t1, &port) != 0 || port > 0xFFFF) {
+        ps("portio: bad port\r\n");
+        ExitProcess(1);
+    }
+
+    if (token(cmd, 2, t2, sizeof(t2)) == 0) {
+        /* 写 */
+        if (parse_num(t2, &val) != 0 || val > 0xFF) {
+            ps("portio: bad value\r\n");
+            ExitProcess(1);
+        }
+        outpb((u16)port, (u8)val);
+        ps("portio: wrote "); ph(val); ps(" -> port "); ph(port); ps("\r\n");
+    } else {
+        u8 v = inpb((u16)port);
+        ps("portio: port "); ph(port); ps(" = "); ph(v); ps("\r\n");
+    }
+    ExitProcess(0);
+    return 0;
+}