Native ABI foundations for BamTiScript.
This module owns the C-layout value representation shared verbatim between
the register interpreter and generated native code. Value constants and
ShadowFrame layout are grounded in the machine-checked formal models:
formal/lean/Bamti/Value.lean— the NaN-boxedWord64field algebra (header:13 || tag:3 || payload:48), the seven nonzero tags, and theencode/decoderound-trip theorem.formal/lean/Bamti/Abi.lean— the 32-byte, 8-alignedShadowFrameheader layout theorem.
Completion and CompletionTag belong to the native-entry contract in the
canonical execution plan (N5); the Lean files do not assign them a wire
layout. Bamti.NodeLoop.Completion is a separate event-loop proof record.
The value/frame primitives in this file are total, allocation-free, and
require no unsafe. The native runtime bridge — the exported bamts_*
helper ABI, the panic- and nesting-safe [native_bridge::NativeOps]
dispatch seam, and the feature-gated JIT/AOT linkage surfaces — lives in
[native_bridge], which centralizes every unsafe operation the generated
code requires.