fix?: enforce flow shift for all schedulers

[stduhpf]

Summary

Applies flow-shift even on sigma-space schedulers.

Related Issue / Discussion

#1669

Additional Information

Example: bong_tangent scheduler (sigma-space)

sd-cli.exe --diffusion-model ..\ComfyUI\models\unet\z_image_turbo-Q8_0.gguf --vae ..\ComfyUI\models\vae\flux\ae.safetensors --llm ..\ComfyUI\models\clip\llms\Qwen3-4b.Q6_K.gguf --cfg-scale 1.0 -v --offload-to-cpu --preview proj --steps 8 --rng cpu --lora-model-dir H:\ComfyUI\models\loras\z-img -W 1024 -H 1024 --color --vae-conv-direct --sampling-method res_2s -p "A lovely cat holding a small 16:9 picture frame" --scheduler bong_tangent --flow-shift [x]`

	--flow-shift 3.0	--flow-shift 1.0
master
PR

smoothstep scheduler (timestep-space)

	--flow-shift 3.0	--flow-shift 1.0
master
PR

Checklist

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