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>

ui/dr-ui/src/presets.rs

@@ -277,15 +277,16 @@ pub fn save_open_edit(
             // note above gives: they are one edit, and a stock read from a
             // session that had already moved on would be a different
             // photograph's.
-            s.film().map(|(stock, print)| dr_pipeline::sidecar::FilmRef {
-                stock: stock.to_string(),
-                print: print.then(|| {
-                    dr_film::find(stock)
-                        .and_then(dr_film::default_print)
-                        .map(|p| p.stock.clone())
-                        .unwrap_or_default()
+            s.film()
+                .map(|(stock, print)| dr_pipeline::sidecar::FilmRef {
+                    stock: stock.to_string(),
+                    print: print.then(|| {
+                        dr_film::find(stock)
+                            .and_then(dr_film::default_print)
+                            .map(|p| p.stock.clone())
+                            .unwrap_or_default()
+                    }),
                 }),
-            }),
         )
     }) else {
         return;