Format the tree the way the gate asks for it

`cargo fmt --check` is a required step and had drifted across 45 files. Most of
it arrived this week: several operations were written in parallel worktrees and
merged by hand, and a hand-merge resolves conflicts without ever running the
formatter over the result.

No behaviour changes — this is `cargo fmt --all` and nothing else, kept as its
own commit so the next reader can skip it wholesale rather than search it for
one that matters.

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

core/dr-gpu/tests/local_contrast.rs

@@ -158,7 +158,12 @@ fn clarity_lifts_local_contrast_and_leaves_the_flat_regions_alone() {
 
     // Far outside the kernel's reach the base equals the pixel, the detail
     // signal is zero, and the output must be the input to the last code value.
-    for x in [0, reach / 2, SIZE as usize - 1 - reach / 2, SIZE as usize - 1] {
+    for x in [
+        0,
+        reach / 2,
+        SIZE as usize - 1 - reach / 2,
+        SIZE as usize - 1,
+    ] {
         assert!(
             edited[x].abs_diff(plain[x]) <= 1,
             "column {x} moved by {} away from any edge",
@@ -246,7 +251,10 @@ fn the_soft_limit_bounds_the_halo_at_a_hard_edge() {
          an unlimited unsharp mask would give"
     );
     // But it is still a real effect, not a control that does nothing.
-    assert!(worst > 0.1, "clarity moved almost nothing: {worst:.3} stops");
+    assert!(
+        worst > 0.1,
+        "clarity moved almost nothing: {worst:.3} stops"
+    );
 }
 
 #[test]
@@ -476,7 +484,11 @@ fn dragging_the_slider_re_runs_the_detail_stage_and_nothing_else() {
     let mut graph = graph_with(CLARITY, 40.0);
     render(&mut pass, &graph, &source, 256);
     assert_eq!(pass.colour_dispatches(), 1);
-    assert_eq!(pass.detail_dispatches(), 2, "a separable mask is two passes");
+    assert_eq!(
+        pass.detail_dispatches(),
+        2,
+        "a separable mask is two passes"
+    );
     let pipelines = pass.cached_detail_pipelines();
 
     for amount in [50.0, 60.0, 70.0] {