Let a detail pass carry a list, not only a kernel

Every neighbourhood pass so far has been a convolution, whose whole
description fits in the uniform block because its structure fixes how many
numbers it needs. Spot removal is not that shape: sixty-four repairs and
one repair are the same shader with a different buffer behind it.

So a pass may declare `storage`, which arrives at binding 3 as
`array<vec4<f32>>` with `arrayLength` in scope. The alternative — packing
the list into uniforms — needs a fixed maximum paid for on every frame, a
composer that can emit vec4 fields because a uniform array's stride is 16
whatever it holds, and it gives the next operation that wants a table
nothing to build on.

The property worth having is what stays out of the generated source: the
count is in the buffer, so placing the tenth spot uploads 512 bytes and
reuses the compiled pipeline, exactly as moving a slider does for the
fused pass. `changing_the_list_does_not_recompile` is that, asserted.

One bind group entry rather than two more layouts, and one placeholder
buffer allocated in `new` rather than sixteen bytes per pass per frame —
a zero-length storage buffer cannot be bound, and per-frame allocation is
what this module's documentation exists to refuse.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

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

@@ -436,6 +436,8 @@ impl DetailStage for NoiseReduction {
             passes.push(DetailPass {
                 label: "luminance",
                 radius: luma,
+                // A convolution, not a list: nothing to bind at binding 3.
+                storage: Vec::new(),
                 uniforms: vec![
                     Uniform {
                         name: "radius",
@@ -474,6 +476,8 @@ impl DetailStage for NoiseReduction {
                         "chroma-vertical"
                     },
                     radius: chroma,
+                    // A convolution, not a list: nothing to bind at binding 3.
+                    storage: Vec::new(),
                     uniforms: vec![
                         Uniform {
                             name: "radius",