Build the Linux LLVM helper and runtime pack before running both test lanes, and align native cache contracts with the current target policy. Full managed Sandbox gate passed.
* Separate native linking from C compilation
- Split the helper-object runtime-pack path into explicit link planning and platform linking.
- Reserve SCRIPTC_LINKER for object-only executable links while retaining a deprecated SCRIPTC_CC compatibility path.
- Add no-legacy-C coverage and document the linker/SDK boundary.
* Preserve runtime pack link errors
* Fix linker cache invalidation and warnings
* Fix C executable cache routing
- Keep explicit C builds on compiler-backed cache identities.
- Cover linker-only environment changes across exact C repeats.
* perf: lazy-load the compiler from the CLI
- Serve help and version from a lightweight bootstrap and route exact executable cache hits before loading the compiler graph.
- Validate routed hits against compiler, frontend, toolchain, and native dependency proofs with portable cache publication.
* fix: repair lazy executable cache routes