FABRIC-3.10.8 MC-1a: the core table, and amd64's second core online and parked

hal/smp.c: dense logical core ids, a heap-sized core table, one-at-a-time
bring-up under a 1 s bound, park-wake reporting at the idle point.
amd64: MADT enumeration, a relocation-free real->long-mode trampoline
copied below 1 MiB, INIT-SIPI-SIPI via the LAPIC ICR; QEMU -smp 2.
Core 1 reports online with GS on its own block, parks with 0 wakes;
aarch64/riscv64 report 1 core until MC-1b/c. 3-ISA acceptance clean.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

include/starkernel/percpu.h

@@ -61,6 +61,12 @@ typedef struct sk_percpu {
     /* K-11 (spinlock.c): locks this core holds right now, per rank -- the
      * lock-order check compares a new lock's rank with the highest held. */
     uint32_t          held_rank[SK_LOCK_RANK_COUNT];
+    /* MC-1 (hal/smp.c): the core's hardware id (APIC id / MPIDR / hartid;
+     * never the lock owner word), and what it reports on coming online. */
+    uint64_t          hw_id;
+    uint64_t          reg_readback;  /* its per-CPU register, read on arrival */
+    volatile uint32_t online;        /* 1 once parked (release store) */
+    volatile uint64_t park_wakes;    /* times woken while parked */
 } sk_percpu_t;
 
 /* Installs the boot core's block in this core's per-CPU register. Call