xregen: use target model's optimal window centered on segment midpoint

Remove pre-truncation from all inference paths — stitch_wavs owns trimming

Fix segment bleed: equal-spaced windows + contact-edge trimming

Fix regen GPU fns: move seg clip extraction inside GPU scope

fix: remove ctx_key from all function signatures — use fn-name-keyed global dict

fix: use UUID-keyed global dict + ctx_key param for ZeroGPU context passing

fix: pass CPU context as ctx_json argument to @spaces.GPU functions

fix: replace threading.local with caller-thread-id dict for ZeroGPU context passing

refactor: replace _cpu_ctx with thread-local storage, deduplicate xregen wrappers, parallel downloads, quiet=True

fix: pre-download BigVGAN vocoder to avoid GPU budget drain on MMAudio cold start

fix: pre-download cvssp/audioldm2 at startup to avoid GPU budget drain

fix: use stream selectors instead of map list in mux_video_audio

debug: expose ffmpeg stderr in mux_video_audio

transcode_for_browser: write H.264 into same upload dir so Gradio file server allows it

transcode_for_browser: return new path in fresh tmp dir to beat Gradio probe race

transcode_for_browser: overwrite in-place to suppress Gradio fallback converter

Fix: map 0:v:0 explicitly in transcode and mux to skip data/timecode streams

Fix: restore transcode-on-upload for browser preview; mux already re-encodes so no conflict

Fix: re-encode video in mux_video_audio instead of stream-copy to handle any input codec

Fix: replace custom transcode with gr.Video format=mp4; remove upload handler

Fix: handle no-audio video in transcode_for_browser; fallback on error

Fix: transcode uploaded video to H.264/AAC on upload for browser preview

Fix: restore regen duration floor to 60s (was regressed to 20s)

Fix: pre-download MMAudio CLIP model at startup to avoid GPU window download

ZeroGPU optimizations, refactoring, and regen UX improvements

Fix xregen_mmaudio abort: raise duration floor and load overhead

Unify all models to 48kHz; remove all FlashSR traces

Replace FlashSR with sinc resampling for ZeroGPU compatibility

Fix HunyuanFoley CLAP tokenizer overflow for long prompts

Fix FlashSR CUDA init: bypass FASR class, load SynthesizerTrn on CPU

Optimize ZeroGPU: move FlashSR to CPU, fix regen 16kHz bug

Move FlashSR inside GPU window, fix xregen routing, refactor helpers

fix: load FlashSR on CPU only to avoid ZeroGPU CUDA init violation

remove: HF token settings section and JS fallback

feat: add FlashSR post-processing to upsample TARO 16kHz → 48kHz

fix: remove CF label from crossfade hatch indicator

fix: move segment color boundary to crossfade midpoint

fix: centre crossfade hatch on color boundary, not after it

fix: correct crossfade indicator position on waveform

feat: add crossfade overlap indicators to waveform display

fix: cap crossfade slider max to 4s and clamp in _build_segments

refactor: extract shared helpers to reduce technical debt

Optimize GPU usage and fix resource leaks

Use Gradio's postMessage zerogpu-headers for regen quota attribution

Fix crossfade loudness bump: apply db_boost to overlap as a whole

Add HF token input for ZeroGPU Pro quota on regen

Fix ZeroGPU Pro quota: fetch fresh x-ip-token before each regen call

fix: relay x-ip-token from HF proxy to JS for ZeroGPU Pro quota attribution

fix: add gr.Request to xregen_* for proper ZeroGPU quota attribution

revert: back to queue/join — call endpoint gives 404 Session not found