feat(stable_diffusion): expose StableDiffusionConfig.unet() and .autoencoder() accessors

Downstream consumers (e.g. mold's single-file SD1.5/SDXL Civitai checkpoint loader) need to construct UNet2DConditionModel and AutoEncoderKL with a custom VarBuilder backend. The configs sit on private fields with no accessor, blocking that path. Adding two read-only accessor methods is the minimal additive fix.

Author: jdilley

Cargo.toml

@@ -15,7 +15,7 @@ exclude = [
 resolver = "2"
 
 [workspace.package]
-version = "0.9.10"
+version = "0.9.12"
 edition = "2021"
 description = "Minimalist ML framework (mold fork with LTX Video models, Metal fixes)."
 repository = "https://github.com/utensils/candle"

candle-transformers/src/models/stable_diffusion/mod.rs

@@ -513,6 +513,16 @@ impl StableDiffusionConfig {
     pub fn build_scheduler(&self, n_steps: usize) -> Result<Box<dyn Scheduler>> {
         self.scheduler.build(n_steps)
     }
+
+    /// Read-only access to the UNet sub-configuration.
+    pub fn unet(&self) -> &unet_2d::UNet2DConditionModelConfig {
+        &self.unet
+    }
+
+    /// Read-only access to the autoencoder (VAE) sub-configuration.
+    pub fn autoencoder(&self) -> &vae::AutoEncoderKLConfig {
+        &self.autoencoder
+    }
 }
 
 pub fn build_clip_transformer<P: AsRef<std::path::Path>>(