Fix CI workflow: use correct rust-toolchain action (#1)

* Fix CI workflow: use correct rust-toolchain action

* Fix CI: resolve Rust compilation and formatting issues
- Fix rust-toolchain action name in CI workflow
- Add missing Direction import in test modules
- Add missing entry_fees argument to open_position test calls
- Comment out nightly-only rustfmt options
- Auto-format code with cargo fmt

tests/test_indicators.rs

@@ -103,23 +103,13 @@ fn test_stochastic_range() {
     // %K and %D should be in [0, 100]
     for (i, &k) in result.k.iter().enumerate() {
         if !k.is_nan() {
-            assert!(
-                k >= 0.0 && k <= 100.0,
-                "%K at index {} is out of range: {}",
-                i,
-                k
-            );
+            assert!(k >= 0.0 && k <= 100.0, "%K at index {} is out of range: {}", i, k);
         }
     }
 
     for (i, &d) in result.d.iter().enumerate() {
         if !d.is_nan() {
-            assert!(
-                d >= 0.0 && d <= 100.0,
-                "%D at index {} is out of range: {}",
-                i,
-                d
-            );
+            assert!(d >= 0.0 && d <= 100.0, "%D at index {} is out of range: {}", i, d);
         }
     }
 }