0.11.4 — Controls for the new multimodal lanes

A follow-up to 0.11.3 that makes the audio and video surfaces controllable, discoverable and reproducible — no new models, just the knobs the new lanes were missing. Every change here was exercised end-to-end on the Studio (M3 Ultra) against the published wheel.

• Video motion controls. POST /v1/videos now accepts guidance_scale, negative_prompt, explicit fps/frames, and (LTX image-to-video) conditioning_strength — each validated against the served backend, so an out-of-range value returns a clear 400 instead of a bad clip (PR #1340).
• Discoverable limits. GET /v1/videos/capabilities reports the served backend's real bounds — the size range and multiple-of-64 rule, the 8n+1 (LTX) and 4n+1 (Wan) frame shapes, native fps, the pixel-frame workload ceiling and the reference-image caps — so a client can size a request without guessing (PR #1343).
• Audio output format. /v1/audio/speech and /v1/audio/music take sample_rate (8k–96k) and channels (mono or stereo); the returned WAV is resampled and up- or down-mixed to match, and echoes the actual rate and channels in X-Audio-* response headers (PR #1346).
• Reproducible designed voices. Qwen3-TTS VoiceDesign accepts a voice_seed, so a voice you described in natural language comes back byte-for-byte identical on the next call — the missing piece for keeping one narrator across a project (PR #1347).
• LTX videos come back video-only. The LTX checkpoint is an audio-video one, but its audio track was silent; that empty track is now stripped so the MP4 is a single video stream instead of reading to downstream tools as "this clip has sound" (PR #1349).
• Docs caught up. The audio guide had five whole model families missing (PR #1345), and the video guide now states plainly that these backends return no audio (PR #1353).