test(gencpp): add full gencpp/base samples and comprehensive test suite

- Copied 58 files from C:\projects\gencpp\base\ to tests/assets/gencpp_samples
- Added test_gencpp_full_suite.py that validates:
  - Skeleton generation for all .hpp files
  - Code outline generation
  - get_definition for key symbols
  - AST masking with aggregation
- All 25 tests pass

tests/assets/gencpp_samples/gen.dep.hpp

@@ -0,0 +1,21 @@
+// This file is intended to be included within gen.hpp (There is no pragma diagnostic ignores)
+#pragma once
+
+#include "dependencies/platform.hpp"
+
+GEN_NS_BEGIN
+
+#include "dependencies/macros.hpp"
+#include "dependencies/basic_types.hpp"
+#include "dependencies/debug.hpp"
+#include "dependencies/memory.hpp"
+#include "dependencies/string_ops.hpp"
+#include "dependencies/printing.hpp"
+#include "dependencies/containers.hpp"
+#include "dependencies/hashing.hpp"
+#include "dependencies/strings.hpp"
+#include "dependencies/filesystem.hpp"
+#include "dependencies/timing.hpp"
+#include "dependencies/parsing.hpp"
+
+GEN_NS_END