Release v4.73.0

Added

• New MCP tool dependency-graph shows how slices, features, modules and other bounded contexts depend on each other, inferred from the model with no new language.
  • Each slice edge has a kind: uses facts from, reacts to, decides from, asks, shows, used in specifications (hidden by default), or outside the model (contract imports).
  • The tool implies edges between modules and features, including mixed levels, with counts and the slice references behind each edge.
  • It reports groups that depend on each other.
  • It suggests a story order that keeps the authored order unless a dependency forces a change. The suggestion is never applied. (part of #414)