feat: add C++ support with ImGui/ImPlot framework and vendor submodules

Añade soporte C++ al registry: vendor submodules (glfw, imgui, implot, tracy),
sistema de build con CMake y toolchains cross-platform, runner C++ en fn CLI,
parser de tests Google Test, y funciones bash para build Linux/Windows.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

bash/functions/infra/install_cpp_deps.md

@@ -0,0 +1,37 @@
+---
+name: install_cpp_deps
+kind: function
+lang: bash
+domain: infra
+version: "1.0.0"
+purity: impure
+signature: "install_cpp_deps() -> void"
+description: "Verifica e instala las dependencias de sistema necesarias para compilar C++ con ImGui (cmake, g++, glfw, mesa)"
+tags: [cpp, dependencies, setup, cmake, imgui]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: []
+tested: false
+tests: []
+test_file_path: ""
+file_path: "bash/functions/infra/install_cpp_deps.sh"
+params: []
+output: "Instala paquetes faltantes via apt o confirma que todo esta instalado"
+---
+
+# install_cpp_deps
+
+Verifica las dependencias necesarias para el build C++:
+- `cmake` — sistema de build
+- `g++` / `build-essential` — compilador
+- `libglfw3-dev` — windowing (GLFW)
+- `libgl1-mesa-dev` — OpenGL headers
+
+Tambien reporta si `mingw-w64` esta disponible para cross-compile a Windows.
+
+```bash
+fn run install_cpp_deps
+```