- Classify Node 24 fetch APIs and options by static, dynamic-only, unsupported, and out-of-scope support.
- Project the inventory into the surface manifest and add runtime drift and conformance checks.
- Fence unprofiled Headers members with actionable SC2020 diagnostics.
- Pin the supported fetch surface to an explicit Node and Undici profile.
- Generate deterministic WebIDL, AbortSignal, and stream differential campaigns.
- Match Node stream pull scheduling while preserving typed source identity.
- Every K-fixture library profile cross-builds through compileLibrary for aarch64-linux-gnu.2.36, x86_64-linux-gnu.2.36, x86_64-windows-gnu, and x86_64-macos, both emissions — 112 archives, ~2min warm, which plus the hard zig requirement is why the lane is env-gated like its linux/windows siblings
- Per archive on the host: K1 symbol exactness against the profile's declared set (Apple's nm is llvm-nm and reads ELF/COFF/Mach-O alike; Mach-O's underscore is the only decoration), the K8 ambient audit in bare and COFF-dllimport spellings, and probe LINKABILITY against the target's libc plus the documented win32 embedder libs
- K2 execution probes ride the existing infrastructure gates: SCRIPTC_LINUX=1 runs the scalar round-trip per linux triple in the bookworm container, SCRIPTC_WIN=1 ships it to the box over scp and folds the mingw CRT's text-mode CRLF back on that one leg
- x86_64-macos stays build-only by contract; the probe runs as a bonus when Rosetta is detected
- README documents the fifth lane beside the linux/windows differentials
