Exposes the `speed` parameter (0.5–2.0) on the TTS `/v1/audio/speech`
request so audio is generated at the target tempo natively via the
faster-qwen3-tts backend rather than post-processing.
- Backend: `/api/tts-preview` now extracts and forwards a `speed`
override (clamped 0.1–4.0) through the same extra-params mechanism
already used for seed/temperature; backends that reject it fall back
cleanly via `_post_tts_with_fallback`.
- Try it out: "Native Speed" number input (0.5–2, step 0.05) added to
the text card; value persists in localStorage per browser; passed as
`extra` through `createTtsAudioSource` and `generateChunkedTts`.
- Read aloud: "Native Speed" control added to the generation controls
row alongside seed/temperature; included in `readerGenParams()` and
saved/restored with library documents (each book tracks its own speed).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Read Aloud (new "Vorlesen" tab):
- PDF (real page render + overlay highlight) / TXT reader with live word
highlighting, voice + speed, per-sentence synthesis-state colours, zoom
(fit-width/height, two-page, ±), resume, and a server-side book library
(syncs across devices; per-unit MP3 audio fetched on demand).
Book -> multi-speaker audiobook:
- "Cast as audiobook" attributes dialogue to characters via the LLM
(guillemet/quote-style aware, turn-taking, recent-context), with a
deterministic speech-tag fallback. Editable preview, non-blocking live
casting panel, then auto-saved as a reopenable Script Rehearser play.
- Audiobook export: synthesise every cast line -> one MP3 per chapter.
Character sheets:
- LLM-extracted, self-filling RPG-style sheets (with page+quote sources)
in both Read Aloud and the Rehearser.
Also: MP3 storage + per-page/sentence export, voice-library "Precompute
embeddings" pre-warm, German "Vorlesen" i18n + flag language toggle,
large-PDF performance (lazy raster, buffer/canvas eviction, yielded parse),
and the Seed Finder changelog entry.
New: routes/reader.py, POST /api/attribute-dialogue, POST /api/character-sheets,
static/js/{reader,audiobook,character-sheets}.js, static/sections/s-reader.html.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
