[ADC-681] Generate and validate native Reflux v1

[wolf75222]

Summary

• generate the canonical native Reflux v1 interface from the component catalog
• expose the exact generated Python/C++ identities, POD request/face descriptors, loader table, and consumer validation
• reject incomplete conformers, malformed face shapes/centering/ownership, invalid logical time, and inconsistent component outcomes before publication
• keep Reflux local and noncollective: PoPS retains topology, MPI, flux-register, transaction, and state-publication authority

History

Implementation and tests remain as separate commits. The branch was refreshed onto current master@d54ed97c with an explicit merge commit; no squash, rebase, amend, or force-push.

Validation

• prior head: complete GitHub Actions matrix green, including all C++/installed-Python shards, MPI prewarms, collective HDF5, and final gate
• current head 1b34f39f: component-catalog generator check passed
• git diff --check: passed
• six installed-package-oriented Python checks were collected but skipped locally because the shared environment still points at a removed historical headers path; they are not counted as proof
• exact-current-head CI is pending; this PR remains draft until it is green

Boundary

This PR defines and validates the Reflux ABI. Runtime execution of the prepared component is stacked separately in PR #638.