Adds _resolve_csharp_type_references (graphify/extractors/csharp.py), the C#
counterpart to _resolve_java_type_references. It re-points dangling
inherits/implements/references edges from no-source shadow stubs onto the real
definitions, disambiguating same-named types across namespaces using the
referencing file's `using` directives + enclosing namespace; ambiguous matches
are refused (unique-hit guardrail), not guessed. Runs after id-disambiguation and
the sourceless-stub rewire, on the ambiguous remainder, behind a log-and-skip
try/except. _CSHARP_CONFIG is broadened to extract enum/struct/record as type
definitions so references to them resolve too.
Ported from PR #1466 by @TheFedaikin. Known follow-up: types declared in
nested/multiple namespaces in one file aren't registered as targets yet (fails
safe — under-resolves to a stub, never mis-resolves). Advances #1318 for C#.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>