style: satisfy cargo fmt and clippy on the fill-handle perf change

cargo fmt reformatted the new example's while-loop condition onto its
own line; clippy's nonminimal_bool caught a negated is_some_and that
reads more plainly as is_none_or.

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

crates/engine/examples/fill_handle_perf.rs

@@ -31,7 +31,8 @@ fn main() {
     let t = Instant::now();
     let mut last = 0u32;
     let mut iters = 0u64;
-    while last + 1 < gridcraft_engine::core::MAX_ROWS && sh.value_ref(CellRef::new(last + 1, neighbour)).is_some_and(|v| !v.is_empty()) && last < cap {
+    while last + 1 < gridcraft_engine::core::MAX_ROWS && sh.value_ref(CellRef::new(last + 1, neighbour)).is_some_and(|v| !v.is_empty()) && last < cap
+    {
         last += 1;
         iters += 1;
     }

crates/model/src/store.rs

@@ -149,7 +149,7 @@ impl CellStore {
             let band_hi = ((band_key + 1) * BAND - 1).min(cap);
             let mut advanced = false;
             for (r, cols) in band.rows.range(expect..=band_hi) {
-                if *r != expect || !cols.get(&from.col).is_some_and(|c| !c.value.is_empty()) {
+                if *r != expect || cols.get(&from.col).is_none_or(|c| c.value.is_empty()) {
                     return last;
                 }
                 last = Some(expect);