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/lib.rs

@@ -518,17 +518,21 @@ fn apply_when_ready(
 pub(crate) fn sync_film(window: &AppWindow, session: &Rc<RefCell<Option<DevelopSession>>>) {
     let choices = DevelopSession::film_choices();
 
-    let chosen = session.borrow().as_ref().and_then(|s| {
-        s.film()
-            .map(|(stock, print)| (stock.to_string(), print))
-    });
+    let chosen = session
+        .borrow()
+        .as_ref()
+        .and_then(|s| s.film().map(|(stock, print)| (stock.to_string(), print)));
 
     // A stock this build has no profile for leaves the picker on "None" rather
     // than inventing an entry for it. The sidecar still carries the name — it
     // is only the *control* that cannot show what it does not have.
     let selected = chosen
         .as_ref()
-        .and_then(|(stock, _)| choices.iter().position(|(id, _)| *id == Some(stock.as_str())))
+        .and_then(|(stock, _)| {
+            choices
+                .iter()
+                .position(|(id, _)| *id == Some(stock.as_str()))
+        })
         .unwrap_or(0);
 
     let can_print = choices