Problem 6 — auxiliary modules

Re-exports all auxiliary sub-modules used by Problem6:

• LaplacianBasics: edge / graph / induced Laplacians, IsEpsLight
• BarrierPotential: BSS barrier potential barrierPotential
• ResolventBound: PSD resolvent trace inequality
• OneSidedBarrier: one-sided barrier lemma (Lemma 6.1)
• ColoringFramework: PartialColoring, pigeonhole bounds
• DynamicColoring: induced-Laplacian monotonicity and positive semidefiniteness
• LoewnerPullback: Loewner pullback to ε-lightness