Records the fork for getting words from audio WITHOUT a serving-time learned
model: (A) words-as-text, or (B) deterministic formant/phonetic decode + taught
vocabulary. Status: Proposed (stub) — deferred, not a committed design. Captures
the problem, the 0-param/decode-not-borrow/refuse-over-fabricate/reviewed-growth
constraints, and the open questions a full ADR must answer. Exists so the
serving path doesn't silently reach for Whisper. Cross-linked from
docs/audio_pipeline_overview.md §9.
