feat: Add Windows/MSVC cross-platform support

[4fuu]

The following is the content of this PR

• Add a cross-platform compatibility layer and Windows support (src/compat/*, std/z_platform.h), covering paths/files/console behaviors.
• Improve build/install flow (Make/CMake) and resolve standard library paths via install prefix.
• Fix Windows-specific issues in REPL/utils/stdlib and address related build errors.

Other changes (not core compatibility/fix work):

• Minor adjustments in parser/codegen/plugin manager.
• Add a test (tests/async_test.zc) and update docs/config (README.md, .gitignore, AGENTS.md).

[4fuu]

It’s worth noting that on Windows you can build the compiler with MSVC, but at the moment you still need GCC/MinGW to compile the C code generated by zc programs.

[Salvakiya]

I want to try this out more thoroughly this weekend. Initially I found the produced zc binary looks for src/std/z_platform.h when compiling and will fail if its not there. Might be cool if it were embedded into the binary somehow but otoh the distribution just requires that z_platform.h is reachable.

But hey this compiled my first try on windows! great job so far!

[Salvakiya]

@4fuu can you update this with main please

[4fuu]

@Salvakiya
Thanks for checking this out!

z_platform.h will be distributed together with the other files under std, so it should be available as long as the standard library files are installed.

I’ve also merged the latest main into this branch now, and added Windows CI as well. Everything should be up to date at this point.

[4fuu]

@Zuhaitz-dev just pinging in case this slipped through — I’ve merged the latest main, resolved conflicts, and added Windows CI.

Everything is green now. Would love to get your thoughts when you have a chance.

[standaell1234-maker]

4fuu:feature/multi-platform-compat

[Salvakiya]

A few thoughts after messing around with windows and MSVC compatability...

1. it should be possible to embed all compatability headers into the transpiler executable in such a way that the codegen pastes the header content into the start of any transpiled code.

2. overuse of #ifdef _WIN32 should be avoided. its possible to do a compatability layer and avoid doing this outside of the abstraction layer

3. MSVC does not support typeof until C23. This greatly hinders MSVC support.