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/desktop/f32io.c

@@ -36,6 +36,10 @@ int f32_read_path_lfn_w(const char *path, u8 **out_data, u32 *out_size) {
     return f32_read_path_lfn(path, out_data, out_size);
 }
 
+int f32_read_file_by_clus_w(u32 clus, u32 size, u8 *out_buf, u32 buf_cap) {
+    return f32_read_file_by_clus(clus, size, out_buf, buf_cap);
+}
+
 int f32_read_path_lfn_to_w(const char *path, u8 *dst, u32 cap, u32 *out_size) {
     int rc = f32_read_path_lfn_to(path, dst, cap, out_size);
     if (rc != 0) slog_num("[f32io] read_to rc=", rc);   /* M1 调试：定位失败步骤 */