feat(hop): add hop ranges and labeling

[lmeyerov]

Summary

• Graph traversal: hop() now supports min_hops/max_hops bounds plus optional hop labels for nodes, edges, and seeds, and post-traversal slicing via output_min_hops/output_max_hops; GFQL safelist/types and the pandas reference enumerator now cover ranges/slices, and fixes keep branch pruning, seeds, and labels consistent across forward/reverse passes.
• Geo/Kepler: Added Mercator projection helper and Kepler encoding builders (encode_kepler* plus dataset/layer/options/config classes) with API docs, examples, and regression tests for map visualization flows.
• Tooling/CI: Lint/type runners resolve interpreters consistently (uv → python -m → bare); GitHub Actions skip python matrices for docs-only tip commits and warm a shared HuggingFace cache with pinned CPU torch for AI tests; UMAP CuPy 13 compatibility tests retained; README/doc polish including hop bounds notebook.

Examples

• Bounded hop with labels and slice:

g.hop(
    nodes=pd.DataFrame({g._node: ['a']}),
    min_hops=2,
    max_hops=3,
    output_min_hops=2,
    output_max_hops=3,
    label_node_hops='hop',
    label_edge_hops='edge_hop',
    label_seeds=True,
)

• GFQL call path:

g.gfql([
  {
    'type': 'Call',
    'function': 'hop',
    'params': {
      'nodes': seeds,
      'min_hops': 1,
      'max_hops': 2,
      'label_node_hops': 'hop',
      'label_edge_hops': 'edge_hop',
    },
  },
])

• Kepler encoding snippet:

from graphistry import KeplerConfig, KeplerLayer
config = KeplerConfig(layers=[KeplerLayer.point(lat='lat', lng='lon')])
g.encode_kepler_config(config).plot()

Testing

• CI: GitHub Actions matrix green (Python 3.8-3.14, lint/type, tests, docs, CodeQL, RTD preview).