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/sdk/include/deshab/boot_context.h

@@ -21,6 +21,7 @@
 #define DSK_BOOT_FLAG_DKM_READY  (1ULL << 1)
 #define DSK_BOOT_FLAG_FAT32_PATH (1ULL << 2)
 #define DSK_BOOT_FLAG_PROBE_INFO (1ULL << 3)
+#define DSK_BOOT_FLAG_PANIC_FALLBACK (1ULL << 4)  /* FUCK [panic] mode=fallback */
 
 /* ---- reserved 槽位索引（dsk_boot_context.reserved[]） ---- */
 #define DSB_BOOT_RESERVED_PE_SERVICE      4u