v2.28.5: Tier 1 umbrella simplification

Highlights

refactor(umbrella): drop 4 deprecated alias directories (#262)

Collapses src/scitex/{ml,reproduce,rng,verify}/ — pure deprecation shims — into a single _DEPRECATED_MODULE_ALIASES dict in the umbrella's __getattr__. −405 / +19 lines. No behaviour change for callers:

Deprecated alias	Resolves to
scitex.ml	scitex.ai
scitex.reproduce	scitex.repro
scitex.rng	scitex.repro
scitex.verify	scitex.clew

All four still warn (DeprecationWarning) on first access. Tier 2 (~30 thin re-export dirs → factory pattern) and Tier 3 (dt/, deferred schema/, module/) follow in subsequent releases.

Other changes

• ci(cla): allowlist LLEmacs identity (#263)