WIP: clarity and texture

Checkpoint committed by the coordinator, not by the authoring agent: the
session hit its API limit mid-task and left this work uncommitted. Committed
so it survives, NOT because it is finished - expect failing tests and
half-applied changes. The agent resumes from here.

core/dr-pipeline/src/ops/mod.rs

@@ -44,12 +44,16 @@ pub mod aberration;
 pub mod colour_mixer;
 pub mod curve;
 pub mod distortion;
+pub mod local_contrast;
 pub mod vignetting;
 
 pub use aberration::Aberration;
 pub use colour_mixer::ColourMixer;
 pub use curve::ToneCurve;
 pub use distortion::Distortion;
+// Clarity and texture are one implementation at two scales; see the module's
+// documentation for why that is two nodes and not one.
+pub use local_contrast::{Clarity, Texture};
 pub use vignetting::Vignetting;
 
 // The declared nodes, plus `helpers` and `chain`. Generated into OUT_DIR by