Compute — Tuza packing/covering

Replay path (no search, no network):

./.venv/bin/python replay_known.py
./.venv/bin/python verify_c7.py
# optional, ~50s: ./.venv/bin/python census_wke.py 7 --labelled

verify_c7.py rebuilds every 8-regular codegree-7 certificate from certs/reduce_c7_8reg.json and checks the three Puleo conditions by edge incidence. It does not import the searcher.

bin/geng is nauty 2.8.9, compiled from the upstream tarball.

file	what
`tuza.py`	exact $\nu,\tau$ (search + CBC)
`wke.py`	bitset WKE / graph6
`census_wke.py`	unlabelled n=5..8 WKE census; optional labelled n=7
`inspect_n8_exceptions.py`	second WKE implementation on the n=8 $\Delta=4$ list
`reduce_codegree.py`	searcher for 8-regular codegree-7 certificates
`verify_c7.py`	independent checker of those certificates
`reduce_c6.py`	incomplete codegree-6 attempt (12 transferable-template failures)
`split_census.py`	`geng -S` split graphs, $(\nu,\tau)$
`regular7_census.py`	7-regular graphs, $(\nu,\tau)$
`certs/c7_8reg_verified.json`	1044 explicit $(S,X)$
`certs/n8_exceptions.json`	the eight connected non-WKE 8-vertex graphs with $\Delta=4$