Port the duskscript language into the engine as src/dusk/script + duskscriptcc

Brings over the duskscript VM and compiler from dusk-vm: the runtime
(core/vm) lives under src/dusk/script, gated by DUSK_SCRIPT and wired into
the engine lifecycle with print()/consolePrint() routed to the console; the
standalone duskscriptcc compiler stays a lean host tool (linux/knulli only).

Collapses int/fixed/bignum into a single float-backed SCRIPT_VALUE_NUMBER
throughout the lexer, compiler, bytecode format and VM, removing the old
int16-rollover fast paths and the type-conversion builtins they needed.

Fixes a real big-endian bug in the bytecode's 32-bit number reader (found
while adding GameCube/Wii endian support via util/endian.h) and converts
src/dusk/script and duskscriptcc to dusk's memory/string/assert utilities,
which surfaced two more latent bugs: a conservative GC stack scan reading
its own local variable's address, and an uninitialized path buffer in
scriptReadScript when the caller path has no directory component.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

test/CMakeLists.txt

@@ -7,6 +7,12 @@ add_subdirectory(animation)
 add_subdirectory(assert)
 add_subdirectory(asset)
 add_subdirectory(console)
+if(
+  DUSK_SCRIPT AND
+  (DUSK_TARGET_SYSTEM STREQUAL "linux" OR DUSK_TARGET_SYSTEM STREQUAL "knulli")
+)
+  add_subdirectory(duskscript)
+endif()
 add_subdirectory(error)
 add_subdirectory(thread)
 add_subdirectory(display)