bump: minor
type: feat
**Windows target** — `ludicc` builds and runs headless programs on Windows, and builds itself there.

- **`--target <triple>`** — a triple naming `windows` selects the Windows runtime; without
  the flag the target is the host, read at run time from `OS=Windows_NT`. The IR still
  carries no triple, so clang assembles it for the machine it runs on.
- **The libc surface, in IR** — on Windows the header emits `emit_win.ludic`, which defines
  the POSIX names the backend calls (`fopen`, `ftell`, `rename`, `opendir`, `mmap`,
  `fmemopen`, `uname`, …) over the UCRT and Win32. Three of them fixed silent breakage
  rather than link errors: `rename` onto an existing file (every `Fs.write_text` after the
  first), a 32-bit `ftell`, and text-mode `fopen` rewriting `\n` as `\r\n`.
- **Known folders** — `Os.save_dir` / `config_dir` are `%APPDATA%\<app>`, `cache_dir` is
  `%LOCALAPPDATA%\<app>`, `temp_dir` is `%TEMP%`, all with forward slashes; a bundle's
  `home` line points at `%APPDATA%\<name>`.
- **The driver** — finds `C:\Program Files\LLVM\bin\clang.exe` when clang is not on
  `%PATH%`, writes `.exe` outputs, speaks cmd.exe for its directory and cleanup commands,
  and reads `argv[0]`, `%PATH%` and `$LUDIC_HOME` with either separator.
- **A window** — `win32.ll` is `cocoa.ll`'s contract over user32: the held-key set and frame
  key in Ludic codes, the mouse in framebuffer pixels with raw input for cursor mode 2,
  cursor hide/lock/confine that lets go when the window loses the foreground, XInput pads
  in SDL order with rescaled deadzones, and the software `win_present`. `win32_gl.ll` puts
  the WGL context on that window with vsync and borderless full screen; a headless build
  links `gl_win_nowin.ll` instead. The process is per-monitor DPI aware.
- **Sound** — `audio_win.ll` is `audio.ll`'s contract over XAudio2: one source voice per
  clip, loops, volume, rate and a balance pan through the output matrix, RIFF WAVE in PCM or
  float. It reads a clip through the asset pack, so a bundled game's first `Audio.load`
  succeeds - AVAudioPlayer takes a filesystem path, which is why macOS cannot.
- **Not yet** — the splash and `App.set_icon` do nothing, and `Http.*` is still a macOS
  platform layer; a Windows build that uses it stops with a message saying so.
- **`Gl.*` on Windows** — `gl_win.ll` makes a WGL 4.1 core context on a hidden window's DC,
  and `gl_thunks_win.ll` (generated by `ludic-dev glgen` beside `gl_thunks.ll`) calls
  every entry point through a table `@lgl_win_load` fills from `wglGetProcAddress`, falling
  back to `opengl32.dll` for the 1.1 functions it will not return. A headless GL program
  renders on the GPU there: `gl_triangle` matches the macOS frame to within one level per
  channel.