fix: propagate pipeline-native failures

[takeokunn]

Summary

• propagate native command, relocation, compile-file, and stdlib loading failures instead of treating them as successful pipeline results
• add deterministic failure-injection coverage for command, relocation, and compile-time error boundaries

Verification

• sibling fixes are merged in cl-cc-codegen-native, cl-cc-binary, and cl-cc-expand; cl-cc CI resolves pinned dependencies independently
• local ASDF execution is unavailable because the workspace lacks the bootstrap sibling systems; GitHub Actions is authoritative

This PR must remain open for maintainer merge.

[takeokunn]

Independent review (separate reviewer agent):

• Found two correctness issues in the initial root diff:
  1. compile-to-native did not call %ensure-compilation-success before writing native output.
  2. Relocation entries were read from the pre-reorder/pre-MIR program instead of the transformed program used for code generation.
• Fixed in 5d04cdf5: compile-to-native now enforces recorded compilation errors before output and obtains relocation entries from the emitted program.
• The review also identified a remaining verification gap: the root failure-injection tests exercise private helper boundaries rather than public compile-to-native/compile-file-to-native APIs, and the command stub injects a condition rather than a nonzero process exit. This remains an integration-test gap.
• Follow-up test-stub correction was pushed as 11d6503f.
• CI: https://github.com/nerima-lisp/cl-cc/actions/runs/37575748642