test(algorithms): add extended features unit tests for path ranking

Add comprehensive test coverage for all new graph property features:

Edge Type MI (3 tests):
- Rare edge types have higher MI than common types
- Edge type MI computed when useEdgeTypes enabled
- Auto-detection of heterogeneous edge types

Temporal Modifier (2 tests):
- Recent edges have higher MI than older edges
- Custom temporal decay rate affects MI correctly

Signed Edges (2 tests):
- Positive edges have higher MI than negative edges
- Custom negative penalty affects MI correctly

Probabilistic Edges (2 tests):
- High probability edges have higher MI
- Probability modifier is multiplicative

Community/Hierarchical (2 tests):
- Same-community edges have higher MI
- Custom community boost affects MI correctly

Multiplex/Multi-layer (1 test):
- MI computed per layer for multiplex graphs

Hypergraph (1 test):
- Hyperedge MI aggregates pairwise node similarities

Traversal Mode (2 tests):
- Undirected traversal finds paths in both directions
- Directed traversal respects edge direction

Weight Mode (2 tests):
- Divide mode reduces score for high-weight edges
- Multiplicative mode applies geometric weight penalty

Combined Features (2 tests):
- Multiple modifiers apply to single edge MI
- All features work together in path ranking

Author: Mearman