fix(csharp): walk primary-constructor parameters for references and calls - #2836

Compared 558df6d57d61cb6ef79c740ec7473c6d953d79a7 (base) against c097479b8552a01d37a4577bc9972ab4ccf9a142 (head).

Covered 3/15 changed functions (12 abstained, 0 never run)

• graphify/build\.py · build: unsupported — not verifiable: all 9 sampled inputs raised on both versions — the function never executed, so 'no divergence' would be vacuous (mostly AttributeError — names the real obstacle, not a sampling gap)
• graphify/build\.py · build_from_json: unsupported — not verifiable: all 6 sampled inputs raised on both versions — the function never executed, so 'no divergence' would be vacuous (mostly NameError — names the real obstacle, not a sampling gap)
• graphify/build\.py · build_merge: unsupported — parameter `graph_path` is annotated `str | Path | None` — outside the synthesizable primitive/collection set
• graphify/dedup\.py · deduplicate_entities: unsupported — not verifiable: all 9 sampled inputs raised on both versions — the function never executed, so 'no divergence' would be vacuous (mostly TypeError — names the real obstacle, not a sampling gap)
• graphify/detect\.py · _load_dir_own_ignore: unsupported — parameter `d` is annotated `Path` — outside the synthesizable primitive/collection set
• graphify/detect\.py · _load_graphifyignore: unsupported — parameter `root` is annotated `Path` — outside the synthesizable primitive/collection set
• graphify/extractors/engine\.py · _extract_generic: unsupported — parameter `path` is annotated `Path` — outside the synthesizable primitive/collection set
• graphify/extractors/engine\.py · _java_annotation_names: unsupported — not verifiable: all 182 sampled inputs raised on both versions — the function never executed, so 'no divergence' would be vacuous (mostly AttributeError — names the real obstacle, not a sampling gap)
• graphify/extractors/engine\.py · _java_collect_type_refs: unsupported — parameter `skip` is annotated `frozenset[str] | None` — outside the synthesizable primitive/collection set
• graphify/extractors/markdown\.py · extract_markdown: unsupported — parameter `path` is annotated `Path` — outside the synthesizable primitive/collection set
• graphify/extractors/resolution\.py · _resolve_go_type_references: unsupported — parameter `root` is annotated `Path` — outside the synthesizable primitive/collection set
• graphify/extractors/resolution\.py · _resolve_java_type_references: unsupported — non-vacuity: domain too small (only 1 distinct inputs exercised, need 3) — 'no divergence' would be near-vacuous

Backend availability notices:

• 2 changed test function(s) excluded from verification (a test is the oracle, not the subject)

Formal verification is advisory: equivalent is a proof over a bounded sound subset; may_equivalent is sampled, not proven; unsupported and error are honest abstentions.