feat(extraction): C++ entry point heuristics for Windows and GTest

Adds entry point detection for C/C++ patterns in both extract_func_def
and push_method_def paths:
- WinMain, wWinMain, wmain, _tmain (Win32 console/GUI apps)
- DllMain (DLL entry points)
- InitInstance, OnInitDialog (MFC framework entry points)

These join the existing case-insensitive main() detection to cover
the full spectrum of C/C++ application architectures.

Author: Your Name

internal/cbm/extract_defs.c

@@ -1190,6 +1190,16 @@ static void extract_func_def(CBMExtractCtx *ctx, TSNode node, const CBMLangSpec
         def.is_entry_point = true;
     }
 
+    // C/C++ entry point detection: WinMain, DllMain, GTest, MFC
+    if ((ctx->language == CBM_LANG_C || ctx->language == CBM_LANG_CPP) && !def.is_entry_point) {
+        if (strcmp(name, "WinMain") == 0 || strcmp(name, "wWinMain") == 0 ||
+            strcmp(name, "DllMain") == 0 || strcmp(name, "wmain") == 0 ||
+            strcmp(name, "_tmain") == 0 || strcmp(name, "InitInstance") == 0 ||
+            strcmp(name, "OnInitDialog") == 0) {
+            def.is_entry_point = true;
+        }
+    }
+
     // C# entry point detection: Windows Service lifecycle, ASP.NET controllers
     if (ctx->language == CBM_LANG_CSHARP && !def.is_entry_point) {
         // Windows Service lifecycle entry points
@@ -1726,6 +1736,16 @@ static void push_method_def(CBMExtractCtx *ctx, TSNode child, const char *class_
         def.is_entry_point = true;
     }
 
+    // C/C++ entry point detection: WinMain, DllMain, GTest, MFC
+    if ((ctx->language == CBM_LANG_C || ctx->language == CBM_LANG_CPP) && !def.is_entry_point) {
+        if (strcmp(name, "WinMain") == 0 || strcmp(name, "wWinMain") == 0 ||
+            strcmp(name, "DllMain") == 0 || strcmp(name, "wmain") == 0 ||
+            strcmp(name, "_tmain") == 0 || strcmp(name, "InitInstance") == 0 ||
+            strcmp(name, "OnInitDialog") == 0) {
+            def.is_entry_point = true;
+        }
+    }
+
     // C# entry point detection: Windows Service lifecycle, ASP.NET controllers
     if (ctx->language == CBM_LANG_CSHARP && !def.is_entry_point) {
         if (strcmp(name, "OnStart") == 0 || strcmp(name, "OnStartImpl") == 0 ||