- fix(#57): sapi removed from default features — plain cargo build
  works on macOS/Linux again
- fix(#58): factory credentials parsing coerces JSON scalars (numbers,
  bools) to strings — {"numSteps": 16} no longer silently empties
  all credentials
- feat(#50): SSML break→silence gaps + mark→on_mark callbacks for
  qwen3-local (segment synthesis with PCM concatenation)
- clippy: chunks_exact→as_chunks on CI's stable (1.99)