@eldrforge/tree-core 0.1.7: publish the new guide + refresh internal deps

Summary

This release is primarily a packaging + documentation update: it adds a new usage guide and ensures it ships with the published npm package, along with small dependency version bumps.

What changed

Documentation now shipped with the package

• Added a new guide at guide/index.md describing the library’s purpose, key exports, and basic usage (building a dependency graph, topological ordering, affected package calculation, and cycle checks).
• Updated the files list in package.json to include guide/, so the guide is included when consumers install from the registry.

Why this matters: users can now rely on having the guide available alongside the installed package (useful for offline/reference access and for tooling that packages node_modules).

Dependency updates

• Bumped @eldrforge/git-tools to ^0.1.18 (from ^0.1.17).
• Bumped @eldrforge/shared to ^0.1.8 (from ^0.1.7).
• Lockfile updated accordingly.

Impact: no expected API changes in @eldrforge/tree-core, but the runtime will pull in newer versions of these dependencies.

Repo / contributor guidance

• Added .cursor/rules/no-local-dependencies.md to discourage file:// dependencies between projects.

Breaking changes

• No breaking changes detected in this range. Public API surface appears unchanged; updates are limited to docs/packaging and dependency version bumps.

Upgrade notes

• If you vendor or audit package contents, note that published artifacts now include guide/ in addition to dist/, README.md, and LICENSE.