experiment: gate per-gpu sweep on control completion

.research/experiments/frontier-workload-regime-taxonomy-20260720.md

@@ -177,6 +177,7 @@ The accompanying mock figure is schematic, not data. Panel A shows the state kne
 - Load-contract correction: the original Fixed-PD surface held request rate per GPU constant, so global arrival rate scaled with TP. The v4 sweep holds global arrival rate constant and is retained as the control that isolates service-topology changes. A matched per-GPU sweep is now required to reproduce the original closed-loop intervention: TP1/TP2/TP4 receive `1x/2x/4x` global arrival rate at the same per-GPU `rho`.
 - Per-GPU low-load materialization: 105 cases = W0--W6 × `rho {0.0025,0.005,0.01,0.02,0.05}` × TP `{1,2,4}` were generated under `traces-per-gpu-low`. Audit passed 105 unique paths, 129 public/private rows per case, digests, arrival alignment, and exact `global_rate / TP = per_gpu_rate`. W0 `rho=0.01` is 0.239375 req/s/GPU, bracketing the original 0.215 req/s/GPU Fixed-PD point with `rho=0.005`.
 - The per-GPU sweep writes to a separate `sim-per-gpu-v1` result root but reuses the completed v4 predictor cache for the same TP/prefix/config. Predictor cache provenance is explicit in every surface manifest; workload results and state ledgers are never shared.
+- `wait_and_dispatch_per_gpu.sh` is active locally as a serial gate. It requires all four exact v4 run directories to contain `finished_at` and exit code zero before probing dash1--dash4 and dispatching the four per-GPU jobs; it does not launch a second sweep while v4 is still consuming CPU.
 - A first materialization attempt rounded both `rho=0.005` and `rho=0.01` to the same `rho0p01` directory. Digest validation stopped before simulator launch; the invalid directories were retained with an `invalid-rho-label-collision` suffix. The label function now preserves up to 12 significant digits and has a regression test.
 
 Current decision: finish the v4 fixed-global-rate control, then reuse its trained predictors for the low-load per-GPU sweep before selecting discriminating real-machine pilot points. No real latency result from vLLM 0.20.2 will be compared with the historical vLLM 0.20.0 baseline until the runtime-version gate is resolved.