v4.0.4 - ramtorch quality improvements, better LTX-2 audio-only training and video validations

What's Changed

• Z-Image example (non-turbo) should use model_flavour=base by @bghira in #2519
• ramtorch: percentage-based offload fix for text encoder moving to CPU and back inadvertently causing device mismatch error by @bghira in #2525
• (#2504) add --gradient_checkpointing_backend=unsloth, default to torch by @bghira in #2521
• bugfix: checkpoint preview page missing validation samples by @bghira in #2522
• [UI] add dataset configuration missing options; allow configuring audio duration for standalone sets by @bghira in #2526
• (#2510) allow mask conditioning_type to work on edit models that require latent conditioning by @bghira in #2520
• adamw_bf16 compatibility with unsloth checkpointing by @bghira in #2530
• unsloth checkpointing: flux2, hv, kv5, ltx2, wan, zim by @bghira in #2533
• ramtorch should disable quantisation and device moving by @bghira in #2532
• enable full ramtorch mode by default for the transformer so flux2 RMSNorm gets offloaded by @bghira in #2531
• fix error when validation is not None by @bghira in #2535
• ltx2: audio-only mode should skip video layers, TREAD, CREPA, and aim for ideal LoRA targets by @bghira in #2534
• ramtorch: fix Gemma3 output corruption by @bghira in #2538
• bypass validation scheduler setup for special models by @bghira in #2539
• torchao: fix int8 weight only quant via pipeline by @bghira in #2540
• add --ramtorch_disable_extensions and --ramtorch_disable_sync_hooks to disable custom features by @bghira in #2541
• prevent double-encoding of captions for audio auto-split dataset by @bghira in #2543
• ui: add audio options for video datasets on models which support a+v by @bghira in #2545
• ui: save gradient checkpointing option by default by @bghira in #2544
• (#2523) validation epoch interval should calculate starting point the same as global step by @bghira in #2546
• (#2524) ui: reduce severity of non-fatal errors by @bghira in #2547
• ramtorch: disable extensions by default for speedup on most systems by @bghira in #2548
• bug: kill complete process tree using psutil, same to how the Stop command works, during Shutdown by @bghira in #2550
• (#2542) add video preview to model card by @bghira in #2551
• LTX-2: allow custom schedules, since validation issue is resolved by @bghira in #2553
• z-image: remove low memory flag which now seems to not be needed by @bghira in #2552
• fix validation error for models like z-image that do not use dynamic shift by @bghira in #2555
• set timestep index to 0 to avoid lookup in scheduler.step by @bghira in #2554
• (#2529) remove LongCat specific phrasing on block swap desc by @bghira in #2556
• (#2527) move checkpointing disk section stuff to advanced subsection by @bghira in #2557
• merge by @bghira in #2549

Full Changelog: v4.0.3...v4.0.4