feat: add FLUX.3 Image Klein and Klein Base support (#2143)

docs/edit.md

@@ -14,6 +14,7 @@ Depending on the architecture, different models handle reference images differen
 | [**Qwen Image Edit**](./qwen_image_edit.md) | `qwen` |
 | **Qwen Image LAYERED** | `qwen_layered` |
 | [**Flux.2 [Dev] / Flux.2 [Klein]**](./flux2.md) | `flux2` |
+| [**FLUX.3 Image Klein / Klein Base**](./flux3.md) | `flux2` |
 | [**Boogu Image Edit**](./boogu_image.md) | `z_image_omni` |
 | **Krea2 (Community Edit LoRAs)** | `krea2_ostris_edit` |
 | [**Mage-Flow-Edit**](./mage_flow.md#image-editing) | `mage_flow` |

docs/flux3.md

@@ -0,0 +1,48 @@
+# How to Use
+
+FLUX.3 Image Klein uses a FLUX.3 diffusion transformer, the FLUX.2 VAE, and Qwen3-VL 4B as the LLM text encoder.
+
+## Download weights
+
+- Download FLUX.3 Image Klein
+    - safetensors: https://huggingface.co/black-forest-labs/flux-3-image-klein/tree/main
+- Download FLUX.3 Image Klein Base
+    - safetensors: https://huggingface.co/black-forest-labs/flux-3-image-klein-base/tree/main
+- Download vae
+    - safetensors: https://huggingface.co/black-forest-labs/FLUX.2-dev/tree/main
+    - The `ae.safetensors` included with FLUX.3 can also be used.
+- Download Qwen3-VL 4B
+    - safetensors: https://huggingface.co/Comfy-Org/Krea-2/tree/main/text_encoders
+    - gguf: https://huggingface.co/Qwen/Qwen3-VL-4B-Instruct-GGUF/tree/main
+
+Use the root `model.safetensors` for the diffusion model.
+
+## Examples
+
+### FLUX.3 Image Klein
+
+The distilled model uses 16 steps and CFG 1.0.
+
+```
+.\bin\Release\sd-cli.exe --diffusion-model ..\models\diffusion_models\flux-3-image-klein.safetensors --llm ..\models\text_encoders\Qwen3-VL-4B-Instruct-Q4_K_M.gguf --vae ..\models\vae\flux2_ae.safetensors -p "a lovely cat holding a sign says 'flux3.cpp'" --cfg-scale 1.0 --steps 16 --sampling-method euler -v --offload-to-cpu
+```
+
+<img src="../assets/flux3/flux3-image-klein.png" />
+
+```
+.\bin\Release\sd-cli.exe --diffusion-model  ..\models\diffusion_models\flux-3-image-klein.safetensors --vae ..\models\vae\flux2_ae.safetensors --llm  ..\models\text_encoders\Qwen3-VL-4B-Instruct-Q4_K_M.gguf -r ..\assets\flux\flux1-dev-q8_0.png -p "change 'flux.cpp' to 'flux3-image-klein.cpp'" --cfg-scale 1.0 --sampling-method euler -v  --offload-to-cpu --steps 16
+```
+
+<img src="../assets/flux3/flux3-image-klein-edit.png" />
+
+Repeat `-r` to use multiple reference images, up to 10. See [Image Editing](./edit.md) for reference-image preprocessing options.
+
+### FLUX.3 Image Klein Base
+
+```
+.\bin\Release\sd-cli.exe --diffusion-model ..\models\diffusion_models\flux-3-image-klein-base.safetensors --llm ..\models\text_encoders\Qwen3-VL-4B-Instruct-Q4_K_M.gguf --vae ..\models\vae\flux2_ae.safetensors -p "a lovely cat holding a sign says 'flux3.cpp'" --cfg-scale 3.5 --steps 20 --sampling-method euler -v --offload-to-cpu
+```
+
+<img src="../assets/flux3/flux3-image-klein-base.png" />
+
+The default discrete scheduler uses the upstream time shift of 6.93 for both models. Use `--flow-shift` to override it.