feat: exhaustive STUB instrumentation - 241 panic sites across VMM/kernel + whitelist alignment

- VMM cluster: XJ3-E/LIN-E/VMM-E/VMX-E/EPT-E/IPC-E/VVB-E (124 sites)

- kernel cluster: TST-E/MM-E/UTRW-E/LAPIC-E/IDT-E/SAS-E/PRB-E/NETST-E/DKM-E (117 sites)

- whitelist fixes: vmm_init env probes E10-E14 fallback, disk_log read-only block path, DSL-E05 non-FAT32 device 0 probe

- QEMU smoke: wizard -> USER.CONF -> login -> desktop ready, zero spurious panic

CODE/UTSM/sched/sched.c

@@ -546,12 +546,16 @@ int utsm_sched_enable(u32 tick_hz) {
 
     if (lapic_timer_init(tick_hz) != 0) {
         log_error("[SCHED] lapic timer init failed, stays cooperative");
+        panic_full("SAS-E04 LAPIC TIMER INIT FAILED",
+                   "utsm_sched_enable: lapic_timer_init failed", 0);
         return -1;
     }
     int vec = lapic_timer_vector();
     if (vec < 0 || irq_register((u8)vec, utsm_tick_handler) != 0) {
         lapic_timer_stop();
         log_error("[SCHED] tick handler registration failed");
+        panic_full("SAS-E05 TICK HANDLER REGISTER FAILED",
+                   "utsm_sched_enable: tick handler registration failed", 0);
         return -2;
     }
     idt_set_exception_hook(utsm_sched_exc_hook);