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/primitives/arithmetic/fuzzer/src/fixed_point.rs

@@ -76,8 +76,8 @@ fn main() {
 			let a = FixedI64::saturating_from_rational(2, 5);
 			let b = a.saturating_mul_acc_int(x);
 			let xx = FixedI64::saturating_from_integer(x);
-			let d = a.saturating_mul(xx).saturating_add(xx).into_inner() as i128 /
-				FixedI64::accuracy() as i128;
+			let d = a.saturating_mul(xx).saturating_add(xx).into_inner() as i128
+				/ FixedI64::accuracy() as i128;
 			assert_eq!(b, d);
 		});
 	}

bizinikiwi/primitives/arithmetic/fuzzer/src/multiply_by_rational_with_rounding.rs

@@ -74,19 +74,21 @@ where
 fn round(f: Fraction, r: Rounding) -> Fraction {
 	match r {
 		Up => f.ceil(),
-		NearestPrefUp =>
+		NearestPrefUp => {
 			if f.fract() < Fraction::from(0.5) {
 				f.floor()
 			} else {
 				f.ceil()
-			},
+			}
+		},
 		Down => f.floor(),
-		NearestPrefDown =>
+		NearestPrefDown => {
 			if f.fract() > Fraction::from(0.5) {
 				f.ceil()
 			} else {
 				f.floor()
-			},
+			}
+		},
 	}
 }
 

bizinikiwi/primitives/arithmetic/fuzzer/src/per_thing_from_rational.rs

@@ -74,19 +74,21 @@ where
 fn round(f: Fraction, r: Rounding) -> Fraction {
 	match r {
 		Up => f.ceil(),
-		NearestPrefUp =>
+		NearestPrefUp => {
 			if f.fract() < Fraction::from(0.5) {
 				f.floor()
 			} else {
 				f.ceil()
-			},
+			}
+		},
 		Down => f.floor(),
-		NearestPrefDown =>
+		NearestPrefDown => {
 			if f.fract() > Fraction::from(0.5) {
 				f.ceil()
 			} else {
 				f.floor()
-			},
+			}
+		},
 	}
 }