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/UTSM/test/utsm_selftest.c

@@ -284,6 +284,52 @@ int utsm_selftest_run(void) {
         log_info("[UTSM] selftest kapi ok");
     }
 
+    /* ==== D6 万物互联：dkm_bus 双向服务总线 ====
+     * 覆盖：表存在/magic、kern.* lookup 命中、probe 命中与缺席、
+     * 内核侧非法注册（BUS-E01/E02 走 panic——selftest 只能验证合法路径，
+     * 违规路径由负向测试专用构建验证）。 */
+    {
+        const dkm_kernel_api *api = dkm_get_kernel_api();
+        if (!api->bus || api->bus->magic != DKM_BUS_MAGIC) {
+            log_error("[UTSM] selftest bus table missing");
+            panic_full("TST-E34 BUS TABLE MISSING",
+                       "utsm_selftest: bus api missing or bad magic", 0);
+            return UTSM_ERR_INVALID;
+        }
+        /* kern.* 播种命中：lookup（必存在语义） */
+        void *fn = 0;
+        u32 ver = 0;
+        if (api->bus->lookup("kern.log.info", &fn, &ver) != 0 || !fn) {
+            log_error("[UTSM] selftest bus kern.log.info lookup failed");
+            panic_full("TST-E35 BUS KERN LOOKUP FAILED",
+                       "utsm_selftest: bus lookup kern.log.info failed", 0);
+            return UTSM_ERR_INVALID;
+        }
+        /* probe 命中（可选语义正例） */
+        if (api->bus->probe("kern.block.read", &fn, &ver) != 0 || !fn) {
+            log_error("[UTSM] selftest bus kern.block.read probe failed");
+            panic_full("TST-E36 BUS KERN PROBE FAILED",
+                       "utsm_selftest: bus probe kern.block.read failed", 0);
+            return UTSM_ERR_INVALID;
+        }
+        /* probe 缺席（可选语义负例：返回 -1，不 panic） */
+        if (api->bus->probe("srv.no.such.thing", &fn, &ver) == 0) {
+            log_error("[UTSM] selftest bus probe negative failed");
+            panic_full("TST-E37 BUS PROBE NEGATIVE FAILED",
+                       "utsm_selftest: probe of absent service unexpectedly hit", 0);
+            return UTSM_ERR_INVALID;
+        }
+        /* 服务数合理（P1 播种 22 条；后续 phase 只增不减） */
+        if (api->bus->count() < 22) {
+            log_error("[UTSM] selftest bus seed count too low");
+            panic_full("TST-E38 BUS SEED COUNT LOW",
+                       "utsm_selftest: bus seeded service count below minimum", 0);
+            return UTSM_ERR_INVALID;
+        }
+        log_hex64("[UTSM] selftest bus services=", api->bus->count());
+        log_info("[UTSM] selftest bus ok");
+    }
+
     /* ==== SCHED-1: O(1) runqueue 语义（合成 TCB，协作式，无 tick） ==== */
     /* ==== SCHED-1 + SCHED-2: runqueue / block-wake（tick 竞态保护） ==== */
     {