Node-breaker topology support for solver-facing bus-branch networks.

This crate provides:

• rebuild_topology — rebuild the bus-branch view of a node-breaker-backed network after switch-state changes.
• project_node_breaker_topology — derive an initial bus-branch projection and connectivity mapping from raw node-breaker topology.

surge-topology

Node-breaker topology processing for Surge.

This crate bridges retained physical node-breaker topology and the solver-facing bus-branch network used by the rest of the workspace. Its main workflow is rebuilding a network after switch-state changes, with a secondary projection API for importer and runtime plumbing.