Suggest Pronunciation

Generate a pronunciation suggestion for a word before saving it as a dictionary entry. Returns a `pronunciation` string suitable for use as the `pronunciation` field when creating a `spelled`-method dictionary entry. The suggestion is deterministic (same word always returns the same result) and is intended as a starting point for human review, not as a production-ready transcription. `language` is accepted to maintain a consistent request shape for future per-locale phonetic rules; it does not affect the current output. `ipa` is always `null` in this version — automatic IPA generation is a planned enhancement.