Development environment setup (#1)

* feat: implement mcpplibs.capi.lua — C++23 module binding for Lua C API

- Add src/capi/lua.cppm (module interface) and src/capi/lua.cpp (implementation)
- Wrap lua.h, lauxlib.h, lualib.h in mcpplibs::capi::lua namespace
- Types: State, Number, Integer, CFunction, L_Reg, L_Buffer, etc.
- Constants: status codes, type tags, operators, GC options, hook masks
- Functions: 100+ bindings covering state, stack, push/access, tables,
  globals, calls, coroutines, GC, debug, auxiliary library, standard libs
- Use extern C wrapper header to fix GCC C++ modules linkage issue
- 97 comprehensive Google Test cases covering all API categories
- 4 examples: basic, table, function, eval
- Update xmake.lua, CMakeLists.txt, CI workflow, README, architecture docs
- Design docs and task breakdown in docs/pr/
- Remove old templates.cppm placeholder module

Co-authored-by: SPeak <sunrisepeak@d2learn.org>

* docs: add mcpplibs-capi-lua agent skill

- SKILL.md: quick start, naming map, core API cheat sheet, common patterns,
  build config, caveats (callback signatures, extern C, inline limitation)
- reference.md: complete API reference with all 15 types, 50+ constants,
  100+ functions organized by category with C API correspondence
- Update skills README to list both available skills

Co-authored-by: SPeak <sunrisepeak@d2learn.org>

* fix(ci): build library first to avoid C++ modules race condition

GCC C++ modules require std.gcm to exist before dependent targets
compile. Build mcpplibs-capi-lua first (serialized) then build
remaining targets in parallel.

Co-authored-by: SPeak <sunrisepeak@d2learn.org>

---------

Co-authored-by: Cursor Agent <cursoragent@cursor.com>

Author: Sunrisepeak

.agents/skills/README.md

@@ -1,12 +1,13 @@
-# mcpp-style-ref Agent Skills
+# mcpplibs Agent Skills
 
-用于指导 Agent 在编写或审查 Modern/Module C++ 代码时遵循 mcpp-style-ref 规范的技能。
+用于指导 Agent 在 mcpplibs 生态中开发的技能集合。
 
 ## 可用技能
 
 | 技能 | 说明 |
 |------|------|
 | [mcpp-style-ref](mcpp-style-ref/SKILL.md) | 面向 mcpp 项目的 Modern/Module C++ (C++23) 命名、模块化与实践规则 |
+| [mcpplibs-capi-lua](mcpplibs-capi-lua/SKILL.md) | Lua C API 的 C++23 模块化绑定 — 类型映射、API 速查、常见模式与构建配置 |
 
 ## 使用方式
 
@@ -15,10 +16,12 @@
 ```bash
 mkdir -p .cursor/skills
 ln -s ../../skills/mcpp-style-ref .cursor/skills/mcpp-style-ref
+ln -s ../../skills/mcpplibs-capi-lua .cursor/skills/mcpplibs-capi-lua
 ```
 
 或安装为个人技能：
 
 ```bash
-ln -s /path/to/mcpp-style-ref/skills/mcpp-style-ref ~/.cursor/skills/mcpp-style-ref
+ln -s /path/to/skills/mcpp-style-ref ~/.cursor/skills/mcpp-style-ref
+ln -s /path/to/skills/mcpplibs-capi-lua ~/.cursor/skills/mcpplibs-capi-lua
 ```