fix(extraction): skip bodiless C++ forward declarations (#1093) (#1095)

A `class Foo;` forward declaration parses as a bodiless class_specifier.
extractStruct (#831) and extractEnum already skip their bodiless forms,
but extractClass did not — so every forward decl across dozens of headers
minted a phantom bodiless `class` node that competed with, and could be
picked as the blast-radius representative over, the single real definition.

Add an opt-in `skipBodilessClass` extractor flag (set only on cppExtractor)
and skip a bodiless class node when it's set, mirroring the struct/enum
skip. The flag keeps this C/C++-scoped: languages where a bodiless class is
a complete definition (Kotlin `class Empty`, Scala `case object`/`trait`)
leave it unset and are unaffected. The body is now resolved once at the top
of extractClass and reused for the member walk.

Regression tests cover the collapse to a single definition, elaborated-type
references creating no phantom, and Kotlin/Scala staying indexed.

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

CHANGELOG.md

@@ -9,6 +9,10 @@ and adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+### Fixes
+
+- C++ forward declarations no longer crowd out the real class definition. A `class Foo;` forward declaration — common in large C++ and Unreal Engine codebases, where a heavily used class is forward-declared across dozens of headers — was indexed as its own class node every time it appeared. So exploring that class returned mostly forward-declaration sites, and could even pick one of them as the representative for blast-radius, burying the actual definition and its members and callers. Bodiless forward declarations are now skipped for C and C++, exactly as forward-declared structs and enums already were, so only the real definition is indexed. Languages where a class with no body is a complete definition — such as Kotlin's `class Empty` and Scala — are unaffected. Thanks @luoyxy for the report and root-cause analysis. (#1093)
+
 
 ## [1.1.6] - 2026-06-30