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

pezkuwi/node/core/pvf-checker/src/lib.rs

@@ -380,14 +380,15 @@ async fn examine_activation(
 	};
 
 	let new_session_index = match runtime_api::session_index_for_child(sender, leaf_hash).await {
-		Ok(session_index) =>
+		Ok(session_index) => {
 			if state.latest_session.map_or(true, |l| l < session_index) {
 				let signing_credentials =
 					check_signing_credentials(sender, keystore, leaf_hash).await;
 				Some((session_index, signing_credentials))
 			} else {
 				None
-			},
+			}
+		},
 		Err(e) => {
 			gum::warn!(
 				target: LOG_TARGET,