style: Migrate to stable-only rustfmt configuration

- Remove nightly-only features from .rustfmt.toml and vendor/ss58-registry/rustfmt.toml
- Removed features: imports_granularity, wrap_comments, comment_width,
  reorder_impl_items, spaces_around_ranges, binop_separator,
  match_arm_blocks, trailing_semicolon, trailing_comma
- Format all 898 affected files with stable rustfmt
- Ensures long-term reliability without nightly toolchain dependency

bizinikiwi/client/utils/src/mpsc.rs

@@ -108,8 +108,9 @@ impl<T> TracingUnboundedSender<T> {
 				.with_label_values(&[self.name])
 				.set(self.inner.len().saturated_into());
 
-			if self.inner.len() >= self.queue_size_warning &&
-				self.warning_fired
+			if self.inner.len() >= self.queue_size_warning
+				&& self
+					.warning_fired
 					.compare_exchange(false, true, Ordering::Relaxed, Ordering::Relaxed)
 					.is_ok()
 			{