test(lens): regression test for unresolved wikilink ghost nodes

[MarcoPorcellato]

Context

GraphVisualizer / NetworkXVisitor currently add NetworkX nodes for wikilinks that do not resolve to an indexed page (see #59). Lock expected behavior with a pytest before or after the fix.

Objectives

• Fixture: single page Src.md with - see [[GhostPage]]
• build_network() with LogseqGraph provided → assert ghost target is not counted as a real page node (or assert group == "unresolved" if that becomes the design)
• get_deep_statistics() should not list phantom pages in largest_pages

Files

• tests/test_lens.py
• Reference: src/logseq_matryca_parser/lens.py

Getting started

1. uv sync --all-extras && make all
2. Mirror patterns from test_graph_visualizer_build_network_creates_expected_topology

Out of scope

• Changing LENS rendering HTML (fix belongs in fix(lens): skip ghost page nodes for unresolved wikilinks #59)

Definition of Done

• make all passes