feat(impact): cross-language blast-radius coverage (22 languages + 14 frameworks) (#708)

Completes the cross-file dependency graph behind impact / affected / explore across all 22 supported languages and 14 web frameworks, validated on real-world repos (measured fair-coverage table added to the README). Per-language resolution + framework resolvers/synthesizers (Lua/Luau require, Shopify OS 2.0 Liquid sections, Delphi forms, Rust cross-module + Rocket macros, Swift Fluent, SvelteKit/Nuxt loader/component conventions, RN/Expo bridges). 0 cross-family false edges, full suite green (1187 passed). See #708.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/extraction/languages/csharp.ts

@@ -4,13 +4,29 @@ import type { LanguageExtractor } from '../tree-sitter-types';
 
 export const csharpExtractor: LanguageExtractor = {
   functionTypes: [],
-  classTypes: ['class_declaration'],
+  // Records are first-class type declarations in modern C# (DTOs, value objects,
+  // MediatR/CQRS messages). `record` / `record class` parse as record_declaration
+  // (reference type → class); `record struct` as record_struct_declaration (value
+  // type → struct). Without these, references to a record never resolve (#237).
+  classTypes: ['class_declaration', 'record_declaration'],
   methodTypes: ['method_declaration', 'constructor_declaration'],
   interfaceTypes: ['interface_declaration'],
-  structTypes: ['struct_declaration'],
+  structTypes: ['struct_declaration', 'record_struct_declaration'],
   enumTypes: ['enum_declaration'],
   enumMemberTypes: ['enum_member_declaration'],
   typeAliasTypes: [],
+  // Namespaces qualify type names so same-named types in different namespaces are
+  // distinguishable (e.g. `ApplicationCore.Entities.CatalogBrand` vs
+  // `BlazorShared.Models.CatalogBrand`). Both block (`namespace Foo { … }`, which
+  // nests its types) and file-scoped (`namespace Foo;`) forms — extractFilePackage
+  // pushes the namespace onto the scope so nested/top-level types pick it up.
+  packageTypes: ['namespace_declaration', 'file_scoped_namespace_declaration'],
+  extractPackage: (node: SyntaxNode, source: string) => {
+    const name =
+      node.childForFieldName('name') ??
+      node.namedChildren.find((c: SyntaxNode) => c.type === 'qualified_name' || c.type === 'identifier');
+    return name ? getNodeText(name, source) : null;
+  },
   importTypes: ['using_directive'],
   callTypes: ['invocation_expression'],
   variableTypes: ['local_declaration_statement'],