ADR-0001 Rev 2: 51-bit PhysAddr layout with concrete sub-unit tables

Remove rack_id (4 bits), rename sip_seg→die_id, shift fields to enable
42-bit local_offset (4 TB per die). Define PE_LOCAL/MCPU_LOCAL/CUBE_SRAM
sub-unit tables for AHBM dies and IOCPU sub-unit table for IOCHIPLET
dies (1 TB window). Supersedes ADR-0031.

Also fixes latent VA/PA confusion in pe_dma pipeline DMA path where
virtual addresses were decoded as physical addresses without MMU
translation — previously masked by coincidental bit-position alignment.

529 passed (+6 recovered), 10 pre-existing failures unchanged.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/kernbench/components/builtin/io_cpu.py

@@ -220,10 +220,10 @@ class IoCpuComponent(ComponentBase):
         return []
 
     def _cube_from_pa(self, pa_val: int, fallback: int) -> int:
-        """Extract cube_id from a physical address, with fallback."""
+        """Extract die_id from a physical address, with fallback."""
         from kernbench.policy.address.phyaddr import PhysAddr
         try:
-            return PhysAddr.decode(pa_val).cube_id
+            return PhysAddr.decode(pa_val).die_id
         except Exception:
             return fallback