sema: r402 pitched (2D) fills/copies + copy-dst divergence witness

Two additions for the memset2d/memcpy_roundtrip and readback classes:

1. Pitched transfers. The CE decoder now captures LINE_COUNT (0x41c),
   PITCH_IN (0x410) and PITCH_OUT (0x414); a fill/copy whose LINE_COUNT is
   > 1 and whose destination pitch exceeds the row length builds a row-wise
   op (svc_fill/svc_copy are thin wrappers around the existing 1D bodies,
   advancing dst by dpitch and src by spitch per row). Each row keeps the
   whole per-page resolution/ledger/guard machinery, and a failed row's
   retry re-runs already-written rows with the same pattern (idempotent).
   A flat transfer carries pitch == row length (or no pitch method) and
   keeps the historical single-run path unchanged. Bounded 'sema-2d' row
   names every 2D op build.

   Note: the current victory_memset2d traffic reaches the engine as GR
   kernels plus per-row 4 KB CE copies, so this capability does not yet
   trigger for that client - it is the correct decoder for the CE-class 2D
   shape (driver channel_utils.c memset2d emits LINE_COUNT/PITCH).

2. DST-DIVERGE witness: when a copy destination resolves from the write
   ledger, a read-only resolver probe cross-checks the answer and logs
   (bounded, gsp_sema_dbg) when the writer's page differs from the live
   resolver's - the 'writer follows the ledger while the reader holds
   another page' shape behind the failed D2H staging class (streams2 c1
   zeros, smiley pass failures). Zero rows fired on r403, so the ledger is
   not the active divergence for that boot; the witness stays for the next
   failing capture.

0 files changed, 0 insertions, 0 deletions