feat: Add enum member extraction support across all language extractors

Extends AST parsing to identify and extract individual enum members/cases for better code analysis. Adds enumMemberTypes configuration to each language extractor with language-specific node types (e.g., 'enum_variant' for Rust, 'enum_case' for PHP, 'enum_entry' for Swift/Kotlin). Implements flexible member name resolution supporting both field-based and identifier-based extraction patterns.

src/extraction/languages/kotlin.ts

@@ -9,6 +9,7 @@ export const kotlinExtractor: LanguageExtractor = {
   interfaceTypes: ['class_declaration'], // Interfaces use class_declaration with 'interface' modifier
   structTypes: [], // Kotlin uses data classes
   enumTypes: ['class_declaration'], // Enums use class_declaration with 'enum' modifier
+  enumMemberTypes: ['enum_entry'],
   typeAliasTypes: ['type_alias'],
   importTypes: ['import_header'],
   callTypes: ['call_expression'],