vgsp-sema: CE USERD layout-only + deferred FB sweep diag (ISSUE-0002)

r46 evidence: in a second session the CE rank0 layout probe at ring+0x10000
read a transient incoherent pair (-EINVAL) at discovery and the old candidate
list immediately latched the stale registered pool-relative offset (another
rank's previous-session USERD, frozen 1/1), hiding every later GP_PUT. For CE
channels enforce the ring-derived layout block only, retry until it reads
coherent, and never fall back to the registered/neighbour candidates. A
bounded (+3s, +33s) FB sweep logs the live put/get block when the layout
never becomes coherent.

0 files changed, 0 insertions, 0 deletions