C imports (stb_image, stb_truetype) compiled via the embedded LLVM
clang library now resolve bionic headers on Android. main.zig auto-
fills target_config.sysroot with the NDK root (mirroring the iOS path
that auto-fills the iOS SDK path); c_import.zig derives the bionic
sysroot inside it and passes `--sysroot <ndk>/toolchains/llvm/prebuilt/<host>/sysroot`
to the embedded clang.
Android link branch in target.zig stops auto-appending entries from the
collected `#library` / `#framework` lists. Most `#library` directives
in the stdlib (`objc.sx`'s `objc :: #library "objc";`, frameworks set
by uikit.sx, etc.) describe Apple-specific intent that's nonsensical on
Android. Users opt into Android-side libs via `opts.add_link_flag(...)`
in build.sx — same shape as how the iOS branch already lists frameworks
in chess's configure_build.
Verified end-to-end: chess game compiles for Android, packages into a
debug-signed APK, installs and launches on Pixel 7 Pro. It crashes in
UIRenderer.init because raw GL calls run before EGL is up — same
architectural gap iOS bridges via the Metal GPU protocol. Next step
is a GLES3 GPU impl or a lazy-init in UIRenderer. 86/86 regression
tests + iOS-sim chess build clean.
- `-F <dir>` CLI flag adds Apple framework search paths (parallel to `-L`).
- `TargetConfig.framework_paths` flows into the iOS link line (`-F<dir>`).
- iOS link adds `-Wl,-rpath,@executable_path/Frameworks` so embedded
frameworks resolve at runtime.
- `createBundle` now takes the framework list; for each one it locates
`<name>.framework` in the `-F` paths and `cp -R`s it into
`<bundle>.app/Frameworks/`.
- `c_import.compileCToObjects` forwards `-target`/`-isysroot` to clang so
`#c_import` works under cross-compile (was using host clang implicitly).
- iOS SDK is auto-discovered once at startup and shared by both the C
compile and the link paths.
- `SX_DEBUG_LINK=1` prints the resolved link argv.
- `library/modules/sdl3.sx`: drop `#library "SDL3"` — linking is now
per-target (build.sx handles `-lSDL3` on macOS, `-framework SDL3` on iOS).
