Audit global bypass reductions for c4 h7

[lieoric]

Scope

This stacked draft formalizes and independently checks three reductions for the unresolved balanced c=4, h=7, k=2 boundary:

• exact critical-pair disabling plus a past/future bypass;
• the two-anchor vector potential and first-sweep energy cuts;
• rainbow transversal deletion and the exact thick-token lift error.

The workflow rebuilds the certified first-exhaustion ledger and runs all three audits on GitHub. These are reductions only; the PR deliberately does not claim universal h7 solvability.

A separate exact five-shard trap-CNF run is still in progress.