Saved voices send ref_text, but Fish Audio requires reference_text.
Derive the canonical parameter while preserving explicit overrides.
Both TTS modes use the shared builder.
Add regression cases and document the parameter alias.
Assisted-by: Codex:gpt-6
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Co-authored-by: localai-org-maint-bot <306269227+localai-org-maint-bot@users.noreply.github.com>