feat: add normalized config tracking and improve command

- Add normalize_to_final_build() to map tune configs to final builds (323/233/332)
- Add normalized_config field to BestCarRecord
- Change CarCounts.by_rid key from String to (String, String) for per-config tracking
- Change CarCounts.guid_to_rid to HashMap<String, HashSet<(String, String)>>
- Extract owned tune configs from my_cars.json (engineMajor/weightMajor/chassisMajor)
- Add improve command: owned cars not yet at final build, sorted by track count
- Strip version prefixes (v2c_/v1c_) from config keys at parse time
- Update dedup check in update_best_car to consider normalized_config
- Add atomic_write helper for safe CSV output
- Delete completed plans/code-review-v2.md
- Apply rustfmt formatting across codebase

src/lib.rs

@@ -41,9 +41,12 @@ pub mod test_utils;
 
 // Re-export all public types and functions for backward compatibility.
 // External code can use `top_drives::Car` etc. without knowing the internal module layout.
-pub use context::{AnalysisContext, CarCounts, compute_car_counts};
+pub use context::{compute_car_counts, AnalysisContext, CarCounts};
 pub use csv_util::{compare_cars, escape_csv_field};
 pub use http::get_file;
 pub use translate::{translate_track_name, translate_track_type};
-pub use types::{AppError, BestCarRecord, Car, TripletKey};
-pub use user_data::{MyCarsData, load_my_cars_data};
+pub use types::{normalize_to_final_build, AppError, BestCarRecord, Car, TripletKey};
+pub use user_data::{load_my_cars_data, MyCarsData};
+
+#[cfg(feature = "test-utils")]
+pub use test_utils::empty_my_data;