v0.4.0

Changed

• One shared install prefix, replacing a per-platform directory
  (<prefix>/linux/debug, <prefix>/android, ...). Headers are
  byte-identical across targets and now install once to <prefix>/include;
  what distinguishes a build is the library file itself, which carries a
  platform+ABI tag from the new cmake/PlatformSuffix.cmake --
  libink_linux_x86_64.a, libink_linux_x86_64_debug.a,
  libink_android_arm64_v8a.a, libink_wasm32.a. Each build contributes its
  own ink-targets-<tag>.cmake alongside the shared ink-config.cmake, which
  resolves the caller's tag through the installed PlatformSuffix.cmake and
  includes the matching one -- so find_package(ink CONFIG) keeps working
  unchanged, a Debug consumer falls back to a Release-only install rather than
  failing outright (the two are ABI-compatible here), and a genuinely missing
  build fails with the list of tags that are installed rather than a bare
  "file not found". The version file is now ARCH_INDEPENDENT, since one file
  serves every platform and the default stamped the builder's word size into
  it -- a wasm32 install would otherwise be rejected by a 64-bit consumer.
  CMakePresets.json's android/wasm presets prepend the shared prefix to
  CMAKE_PREFIX_PATH ahead of their own toolchain-installed prefix, so a
  dependency resolved from the shared location doesn't shadow one the
  toolchain provides.