Typed Closure Graphs, Obstruction Propagation, Reopening, and Frontier Contraction

CSM’s first graph-operations core. Argues that an ordinary directed graph cannot carry a mature proof-space closure state, and that a typed directed hypergraph is needed instead (multiple premises, multiple outputs, conditional, versioned edges). Defines, on this hypergraph, implication closure, equivalence-quotient closure, conditional closure, obstruction-propagation closure, bridge-mediated closure, the reopening operator, frontier contraction, debt propagation, the closure ledger, and the relative path-exhaustion certificate. Core non-collapse principle: RouteBlocked ≠ ClaimRefuted ≠ BranchClosed ≠ DomainClosed — an obstruction can propagate along a dependency edge as a theorem-level obstruction only when hypotheses, scope, representation, bridging, and target fidelity are all aligned; otherwise it is only a locally-obstructed state, and must never be upgraded into a theorem-level impossibility result. Also includes NS compilation rules for converting legacy document labels (NO-GO, OPEN, SURVIVOR, CONDITIONAL, CLOSED) into typed nodes/hyperedges/obstruction certificates.