P132 - Dispatch payload record

P132 extends the state-owning dispatch queue module with a one-deep payload record per class. The module now captures PC, opcode, rd, rs1, rs2, and source-use bits on arrival fire.

The shell workload passed:

P132-FILE-OK @ cycle 218,410,599
post-load cycles  : 218,410,456
shell window      : 64,505,052
instr retired     : 86,240,322
CPI               : 2.5326

Payload accounting stayed clean:

payload accepts                : 22,654,694
payload services               : 22,654,627
payload flush clears           : 66
payload append without storage : 0
payload invariant errors       : 0
max occupancy                  : 1 / 1 / 1

This keeps the refactor honest: the queue module now owns a real work record, but it still proves under Linux that the old counters and the new module agree.