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>

tests/test_va_integration.py

@@ -39,7 +39,7 @@ _CFG = AddressConfig(
 
 def _make_allocators(num_pe: int = 8) -> dict[tuple[int, int, int], PEMemAllocator]:
     return {
-        (0, 0, i): PEMemAllocator(rack_id=0, sip_id=0, cube_id=0, pe_id=i, cfg=_CFG)
+        (0, 0, i): PEMemAllocator(sip_id=0, die_id=0, pe_id=i, cfg=_CFG)
         for i in range(num_pe)
     }