whole-function comptime folding for zero-runtime value calls

LANGUAGE.md

@@ -209,6 +209,7 @@ exactly once. Bare functions named `memcopy` or `memset` remain ordinary user fu
 - later comptime value parameters may depend on earlier type parameters, as in `factory func($T type, $default T) type`
 - comptime parameters may appear anywhere, are erased from the runtime ABI, and accept recursively stable booleans, integers, floats, types, immutable bytes, enums, fixed arrays, records/tuples, optionals, tagged unions, and bare function identities; equal structural values and aliases of one function declaration share specializations, while distinct declarations remain distinct and pointers, general slices, fallibles, ranges, untagged unions, and undefined values have no stable comptime identity
 - comptime parameters may be omitted when uniquely recoverable from runtime arguments, the immediate expected result, or exact type-factory provenance; `_` is an explicit inference hole
+- direct bodyful value calls with no runtime parameters, including parameterless and all-`$` functions, are evaluated at comptime when their resolved result can materialize; otherwise they retain their zero-argument runtime specialization, while a reached `compile_error!` remains a diagnostic
 - forced typed comptime expressions such as `$sum(1, 2)`, `$Point { x = 1, y = 2 }`, and comptime value blocks such as `${ yield 4 }`
 - comptime execution for bodyful Brolang functions with mutable locals, loops, `defer`, `match`, `try`/`catch`, exact type `==`/`!=`, pointer/slice storage mutation, pointer captures, and calls through comptime-known function values; `undefined` storage may be initialized at comptime, but remaining poison cannot be observed
 - comptime type factories such as `Box func($T type) type { return struct { value T } }`; calls like `Box(i32)` are concrete nominal types and may appear anywhere a type is expected
@@ -259,7 +260,6 @@ exactly once. Bare functions named `memcopy` or `memset` remain ordinary user fu
 
 ## PLANNED / DEFERRED
 
-- native Brolang variadic functions
 - exporting Brolang functions to C and broader target-specific C ABI lowering
 - non-plain C record layouts such as bitfields, packed records, flexible arrays, qualified fields, and C variadic record arguments
 - arenas, pools, build-mode heap policy, and escaping-allocation diagnostics