P131 - Dispatch queue module extraction

P131 adds p131_dispatch_queue_module3, a state-owning shadow dispatch queue module. It still has no architectural effect, but it moves one state cluster out of the monolithic core body and proves the move under the Linux BusyBox shell workload.

The workload passed:

P131-FILE-OK @ cycle 218,216,022
post-load cycles  : 218,215,879
shell window      : 64,299,031
instr retired     : 86,172,041
CPI               : 2.5323

The new module matched the P130-style contract helper exactly:

samples                 : 64,676,692
arrival-fire cycles     : 22,634,431
service-fire cycles     : 22,634,358
backpressure cycles     : 0
dual/triple ready cycles: 0 / 0

integer fires           : 13,086,378 arrival / 13,086,378 service
memory fires            : 3,242,636 arrival / 3,242,563 service
control fires           : 6,305,417 arrival / 6,305,417 service
max occupancy           : 1 / 1 / 1
flush clears            : 72

This is the top.sv cleanup pattern: move one state owner, compare it against the old accounting, then continue only after Linux still passes.