BT constants

reads the compile-time constants and lightweight cache constants of the current BT runtime.

Parameters	Type	Required	Default value	Description
None	-	No	None	Constant properties require no parameters.

Constant	Type	Description
BT.VERSION	String	The current BT version.
BT.NAME	String	Current binary logical name, usually `bt` or `bt_app`.
BT.OS	String	Operating system name, such as windows, linux, macos.
BT.ARCH	String	CPU architecture, such as x86_64, aarch64.
BT.FAMILY	String	Operating system family, such as windows, unix, wasm.
BT.DEBUG	Bool	Whether to build for debug.
BT.EXE_EXT	String	Current platform executable file extension, such as `.exe` or empty string.
BT.LIB_EXT	String	Current platform dynamic library extension, such as `.dll`, `.so`, `.dylib`.
BT.POINTER_WIDTH	Int	Pointer width, usually 32 or 64.
BT.THREADS	Int	Number of available parallel threads, cached after first read.

- BT.THREADS uses runtime caching and does not query the system repeatedly on each read.