C ABI

Predictable layout for C interop.

Generate headers, dump structured ABI manifests, and verify field offsets before shipping native boundaries.

Current contract

`int` maps to `int64_t`, `float` maps to `double`, and `char` maps to `uint8_t`.
Pointers are pointer-sized and 8-byte aligned on the current x64 release targets.
Struct fields are laid out in declaration order with C-style alignment and tail padding.
Fixed arrays are inline struct storage and keep the element alignment.

Commands

ABI workflow

tezzc cheader tests/conformance/abi/starter_abi.tn build/starter_abi.h
tezzc abidump tests/conformance/abi/starter_abi.tn build/starter_abi.tnx
tezzc abiverify tests/conformance/abi/starter_abi.tn build/starter_abi.tnx

Manifest gate

`abidump` emits schema `tezznative.abi.v1` with struct size, alignment, field offset, field type shape, function return type, and parameter type shape data.

Windows and Linux CI run `cheader`, `abidump`, and full `abiverify` against the published SDK compiler.