fix(extraction): index TypeScript interface members (#1638) (#1780)

Land upstream #1686 (maxmilian + bompus kernel/CG-28 follow-ups)
onto current main. tree-sitter-typescript interface members
(method_signature / property_signature) were never listed in the
TS extractor, so platform .d.ts APIs had no declaration nodes for
call edges. Mirrors on the Rust kernel path; keeps CG-28 damping
for pure-interface declaration files; filters damped files from
the explore RWR seed set.

Co-authored-by: Colby McHenry <colbymchenry@users.noreply.github.com>

src/extraction/languages/typescript.ts

@@ -41,8 +41,15 @@ export function classifyTsClassMember(node: SyntaxNode): 'method' | 'property' {
 export const typescriptExtractor: LanguageExtractor = {
   functionTypes: ['function_declaration', 'generator_function_declaration', 'arrow_function', 'function_expression', 'generator_function'],
   classTypes: ['class_declaration', 'abstract_class_declaration'],
-  methodTypes: ['method_definition', 'public_field_definition'],
+  // `method_signature` is the interface/type-literal form of a method; without it
+  // an interface's members never enter the graph, so a `.d.ts` platform API has
+  // no declaration node for call sites to attach to (#1638). Java/C# don't need
+  // an equivalent — their grammars reuse `method_declaration`.
+  methodTypes: ['method_definition', 'public_field_definition', 'method_signature'],
   classifyMethodNode: classifyTsClassMember,
+  // The interface counterpart of `public_field_definition`. It carries no value,
+  // so it is always a property and never needs classifyMethodNode.
+  propertyTypes: ['property_signature'],
   interfaceTypes: ['interface_declaration'],
   structTypes: [],
   enumTypes: ['enum_declaration'],