ci: format parser.rs under stable 1.96 to make rust-ci green (follow-up) (#44)

## Summary

Follow-up to the merged CI-green PR (#43). With rust-ci now actually
running, `cargo fmt --all -- --check` fails on `main` under the CI
toolchain (stable rustfmt 1.96) — the toolchain-pin PR landed before the
formatting fix did. This brings `src/codegen/parser.rs` to rustfmt-clean
so rust-ci goes green.

## Changes

- **Rust hygiene:** `cargo fmt` (`src/codegen/parser.rs`) so `cargo fmt
--all -- --check` passes under stable 1.96.

## RSR Quality Checklist

### Required
- [x] Tests pass (`cargo test --locked --all-targets`)
- [x] Code is formatted (`cargo fmt --all -- --check`)
- [x] Linter is clean (`cargo clippy --locked --all-targets -- -D
warnings`)
- [x] No banned language patterns
- [x] SPDX license headers present on modified files
- [x] No secrets, credentials, or `.env` files included

## Testing

Verified locally with the CI toolchain (rustc/clippy/rustfmt 1.96.0):
`cargo fmt --check`, `clippy -D warnings`, `cargo check --locked`,
`cargo test --locked` all pass.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---
_Generated by [Claude
Code](https://claude.ai/code/session_01A6PSzJWpRxtzGDjUCEh7Mx)_

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: hyperpolymath

src/codegen/parser.rs

@@ -258,19 +258,46 @@ mod tests {
         let spec = sample_spec();
         let func = parse_function(&spec).expect("TODO: handle error");
         assert!(func.decreases.is_some());
-        assert_eq!(func.decreases.expect("TODO: handle error").expression, "arr.Length");
+        assert_eq!(
+            func.decreases.expect("TODO: handle error").expression,
+            "arr.Length"
+        );
     }
 
     #[test]
     fn test_parse_target_all_valid() {
-        assert_eq!(parse_target("csharp").expect("TODO: handle error"), TargetLanguage::CSharp);
-        assert_eq!(parse_target("cs").expect("TODO: handle error"), TargetLanguage::CSharp);
-        assert_eq!(parse_target("java").expect("TODO: handle error"), TargetLanguage::Java);
-        assert_eq!(parse_target("go").expect("TODO: handle error"), TargetLanguage::Go);
-        assert_eq!(parse_target("python").expect("TODO: handle error"), TargetLanguage::Python);
-        assert_eq!(parse_target("py").expect("TODO: handle error"), TargetLanguage::Python);
-        assert_eq!(parse_target("js").expect("TODO: handle error"), TargetLanguage::Js);
-        assert_eq!(parse_target("javascript").expect("TODO: handle error"), TargetLanguage::Js);
+        assert_eq!(
+            parse_target("csharp").expect("TODO: handle error"),
+            TargetLanguage::CSharp
+        );
+        assert_eq!(
+            parse_target("cs").expect("TODO: handle error"),
+            TargetLanguage::CSharp
+        );
+        assert_eq!(
+            parse_target("java").expect("TODO: handle error"),
+            TargetLanguage::Java
+        );
+        assert_eq!(
+            parse_target("go").expect("TODO: handle error"),
+            TargetLanguage::Go
+        );
+        assert_eq!(
+            parse_target("python").expect("TODO: handle error"),
+            TargetLanguage::Python
+        );
+        assert_eq!(
+            parse_target("py").expect("TODO: handle error"),
+            TargetLanguage::Python
+        );
+        assert_eq!(
+            parse_target("js").expect("TODO: handle error"),
+            TargetLanguage::Js
+        );
+        assert_eq!(
+            parse_target("javascript").expect("TODO: handle error"),
+            TargetLanguage::Js
+        );
     }
 
     #[test]