lattice-common

Shared types, configuration, and error handling for the Lattice scheduler.

This crate defines the core domain model used across all Lattice components:

• Allocation: The universal work unit (replaces Slurm job + K8s pod)
• Node: Physical compute node with capabilities and ownership
• Tenant: Organizational boundary with quotas
• VCluster: Logical cluster with its own scheduling policy
• TopologyModel: Slingshot/UE dragonfly group structure