[r3dbars]

Addresses the narrow cleanup in SUPPORT-10: removes unused speaker-embedder choice titles/summary and the unobserved change notification. This is the isolated one-file hunk from unmerged broad draft #2336.

The setter remains: three test call sites, including one in a loop, use it to seed real preference-resolution contracts. The preference key, raw model cases, defaults, environment precedence, model loading and separate speaker databases stay intact. No Settings or Speakers controls change. This does not claim the setter was removed.

Validation at head d8e1bbc86dd116b7492b35c057c13e01515081f0, against main 8a38235:

• Independent full-diff, whole-owner and caller/reference review; exact candidate/committed blob association verified.
• One guarded canonical check: 15 PASS / 1 FAIL, overall FAIL. The only failure is the full fast suite refused with exit 3. The real app build, strict-concurrency typecheck and mapped static checks passed.
• Raw exact-head proof archived before preflight and verifier; both exited 0. Verifier's speed check was SKIP because Transcripted is already running; nothing was quit. Outer full bench was refused with exit 3.
• Head/source stayed clean and stable. Existing preference tests were not run; CI execution remains pending. No preferences, model, database or native runtime fixture, --list, new assertion or mutation run was used.

Draft; needs owner review. No merge or release.