feat: expose igraph 0.10 functions - `any_mutual()`, `invalidate_cache()`, and 8 generator functions

[Copilot]

Exposes priority 0 functions and new graph generators from igraph 0.10 for the first R release based on 0.10.

Functions Added

Priority 0:

• any_mutual() - checks if directed graph has any mutual edges (wraps igraph_has_mutual)
• invalidate_cache() - invalidates cached properties for debugging

Generators (with make_ prefix):

• make_wheel() - wheel graph
• make_circulant() - circulant graph
• make_turan() - Turán graph
• make_generalized_petersen() - generalized Petersen graph
• make_full_multipartite() - complete multipartite graph
• make_regular_tree() - regular tree
• make_symmetric_tree() - symmetric tree with level-specific branching
• make_triangular_lattice() - triangular lattice

Implementation

• Added public wrappers in R/make.R, R/structural-properties.R, R/utils.R
• Updated tools/stimulus/functions-R.yaml and regenerated bindings via Stimulus
• Handled multi-return functions (make_turan, make_full_multipartite) that return both graph and vertex type attributes

Example

# Check for mutual edges
g <- make_graph(c(1, 2, 2, 1), directed = TRUE)
any_mutual(g)  # TRUE

# Create graph generators
wheel <- make_wheel(10)  # 10 vertices, 18 edges
turan <- make_turan(12, 3)  # 12 vertices split into 3 partitions
V(turan)$type  # partition membership

Not Included

• make_hexagonal_lattice() - not yet in cigraph's interfaces/functions.yaml
• Functions already exposed: is_forest(), is_acyclic(), graph_center(), hits_scores(), weighted radius()/eccentricity()

Original prompt

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This section details on the original issue you should resolve

<issue_title>0.10 functions that should be exposed</issue_title> <issue_description>## Priority 0

This is a list of functions that are new in 0.10 and should probably be exposed in the very first R/igraph release based on 0.10. Should be easy through auto-generation. The igraph_ part is omitted from function names.

• [x] is_forest and is_acyclic
• [ ] has_mutual -> any_mutual
• [ ] invalidate_cache — we need this for debugging
• [ ] ... ?

Priority 1

These would be nice to expose soon though perhaps not in the first release. Several of these were requested by users. Auto-generation is not always possible.

• [ ] hub_and_authority_scores to replace separate hub and authority score calculation
• [x] get_k_shortest_paths igraph/rigraph#972
• [ ] graph_center
• [ ] ... ?

Add support for extra features to existing functions. These are often a separate function in C, but should be integrated into the same function in R.

• [ ] radius_dijkstra and eccentricity_dijkstra (i.e. weight support for both, igraph/rigraph#893)
• [ ] distances_cutoff (cutoff support)
• [ ] ... ?

Generators (probably all of these can be auto-generated):

• [ ] circulant
• [ ] turan
• [ ] wheel
• [ ] full_multipartite
• [ ] regular_tree
• [ ] symmetric_tree
• [ ] triangular_lattice
• [ ] hexagonal_lattice
• [ ] generalized_petersen
• [ ] ... ?

</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes igraph/rigraph#912

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[szhorvat]

This is exposing stuff that there's already another PR for, such as full_multipartite.