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/arch/x86_64/idt.c

@@ -560,6 +560,8 @@ int irq_vector_alloc(void) {
         return vec;
     }
     log_warn("[IDT] vector alloc failed: pool exhausted");
+    panic_full("IDT-E01 VECTOR POOL EXHAUSTED",
+               "irq_vector_alloc: dynamic vector pool exhausted", 0);
     return -1;
 }