condor-pathfinding-core 0.4.0

Neutral cross-domain pathfinding primitives shared by Condor algorithm crates.
Documentation
# Core crate

## Mission

Keep `condor-pathfinding-core` (`condor_core`) a narrow, dependency-free home
for neutral cross-domain primitives.

## Scope

Own shared search outcome/cost/statistics contracts and `Point2`; every domain
crate may depend on this crate.

## Do

- Keep contracts generic, small, and source-unit tested beside their code.
- Add an integration target only for a genuine cross-module core contract.

## Do not

- Do not depend on a domain crate, the facade, harness, bench, or Lab.
- Do not add domain algorithms, fixtures, corpus loaders, or capture/report code.

## Validation

Use `just test-core-lib` and `just clippy-core-lib` for core changes.

## Related

`Cargo.toml`, `src/lib.rs`, `src/search.rs`, and `CONTRIBUTING.md` define this
bottom-layer boundary.

## Escalate when

Moving a domain type here would make core depend on domain semantics rather
than a neutral primitive.