Emit floats an f32 can hold, and drop the format! that formats nothing

CI runs cargo fmt --check and clippy -D warnings, and this branch had
never been through either. Both would have failed it.

The bulk was the generated colour tables: eight significant figures where
an f32 carries about 7.2, so the eighth is noise that rounds away at
compile time and clippy's excessive_precision says so 109 times over.
Fixed in the generator rather than only in the file, so it stays fixed --
and the file is trimmed in place rather than re-derived, because
regenerating it needs a colour-science stack that has nothing to do with
the defect.

The format! in the composer is mine too, from extracting the rendering
tail: the braces in it were escaped because the text used to live inside a
larger template, and once extracted the escapes are noise and the call
formats nothing.

Also here, and clearly not mine: an unused import and a shadowed binding
in dr-gpu, and an unused import in a test. They are pre-existing --
clippy has been failing on master before this branch existed, on lints
like is_multiple_of that arrived with a toolchain rather than with
anyone's code. Fixed because CI cannot go green around them, and called
out because a merge commit is a bad place to quietly edit someone else's
crate.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

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

@@ -201,14 +201,32 @@ impl Operation for FilmSim {
         let mut out = Vec::with_capacity(MATRIX_FIELDS.len() + 5);
         for (l, row) in m.iter().enumerate() {
             for (c, v) in row.iter().enumerate() {
-                out.push(Uniform { name: MATRIX_FIELDS[l][c], value: *v });
+                out.push(Uniform {
+                    name: MATRIX_FIELDS[l][c],
+                    value: *v,
+                });
             }
         }
-        out.push(Uniform { name: "log_min", value: t.curve_log_min });
-        out.push(Uniform { name: "log_max", value: t.curve_log_max });
-        out.push(Uniform { name: "density_max", value: t.density_max });
-        out.push(Uniform { name: "lut_size", value: t.lut_size as f32 });
-        out.push(Uniform { name: "print_exposure", value: self.print_exposure });
+        out.push(Uniform {
+            name: "log_min",
+            value: t.curve_log_min,
+        });
+        out.push(Uniform {
+            name: "log_max",
+            value: t.curve_log_max,
+        });
+        out.push(Uniform {
+            name: "density_max",
+            value: t.density_max,
+        });
+        out.push(Uniform {
+            name: "lut_size",
+            value: t.lut_size as f32,
+        });
+        out.push(Uniform {
+            name: "print_exposure",
+            value: self.print_exposure,
+        });
         out
     }