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-decode/src/base_curve.rs

@@ -487,7 +487,8 @@ mod tests {
             // And the last span is shallower than the one before it, which is
             // what a shoulder *is*. Without one the curve clips highlights
             // harder than the linear rendering did.
-            let slope = |i: usize| (curve.ys[i + 1] - curve.ys[i]) / (curve.xs[i + 1] - curve.xs[i]);
+            let slope =
+                |i: usize| (curve.ys[i + 1] - curve.ys[i]) / (curve.xs[i + 1] - curve.xs[i]);
             assert!(
                 slope(POINTS - 2) < slope(POINTS - 3),
                 "{name} has no highlight shoulder"
@@ -502,13 +503,7 @@ mod tests {
         // as a dark halo in a gradient, which reads as a rendering fault
         // rather than as a bad profile.
         assert_eq!(
-            BaseCurve::from_points(&[
-                [0.0, 0.0],
-                [0.25, 0.4],
-                [0.5, 0.3],
-                [0.75, 0.8],
-                [1.0, 1.0]
-            ]),
+            BaseCurve::from_points(&[[0.0, 0.0], [0.25, 0.4], [0.5, 0.3], [0.75, 0.8], [1.0, 1.0]]),
             None
         );
     }
@@ -540,13 +535,7 @@ mod tests {
         // point above 1.0 would put the shoulder outside the range the curve
         // is defined over and silently flatten everything below it.
         assert_eq!(
-            BaseCurve::from_points(&[
-                [0.0, 0.0],
-                [0.25, 0.3],
-                [0.5, 1.4],
-                [0.75, 1.5],
-                [1.0, 1.6]
-            ]),
+            BaseCurve::from_points(&[[0.0, 0.0], [0.25, 0.3], [0.5, 1.4], [0.75, 1.5], [1.0, 1.6]]),
             None
         );
     }