docs: update documentation for normalized config and improve command

- Add improve command to all command tables and usage sections
- Add normalized_config field to BestCarRecord struct documentation
- Update CarCounts.by_rid type from String to (String, String)
- Update CarCounts.guid_to_rid type to HashMap<String, HashSet<(String, String)>>
- Add owned_configs field to MyCarsData and CarCounts docs
- Add normalize_to_final_build() to API docs
- Update CSV format examples to include FinalBuild column
- Update my_cars.json structure with engineMajor/weightMajor/chassisMajor
- Update timing file example with v2c_ version prefix
- Add version prefix stripping to data transformation docs
- Update CHANGELOG.md with Unreleased section
- Fix compare_records description to include normalized config sorting

README.md

@@ -7,6 +7,7 @@ A comprehensive Rust-based tool for analyzing car performance data in the Top Dr
 - **Best Car Analysis**: Find the best performing cars across all tracks and conditions
 - **Wishlist Optimization**: Identify cars to add to or remove from your wishlist
 - **Collection Cleanup**: Identify cars that can be safely removed from your collection
+- **Upgrade Prioritization**: Find owned cars not yet at their final tune build
 - **Track-Specific Analysis**: Get detailed performance data for specific tracks and conditions
 - **RQ-Based Filtering**: Filter results by car rarity (RQ) levels
 - **Multiple Surface Types**: Support for Dry, Wet, Dirt, Snow, and other track conditions
@@ -75,6 +76,11 @@ A comprehensive Rust-based tool for analyzing car performance data in the Top Dr
    cargo run --bin records -- wishlist
    ```
 
+6. **Upgrade Prioritization**: Find cars that need upgrading
+   ```bash
+   cargo run --bin records -- improve
+   ```
+
 ## 📖 Usage Guide
 
 ### Basic Commands
@@ -140,7 +146,7 @@ cargo run --bin records -- wishlist --max-wishlist 500
 ```bash
 cargo run --bin records -- all
 ```
-Generates all 6 CSV files in a single parse pass. Equivalent to running `best`, `trash`, and `wishlist` together, but more efficient.
+Generates all 7 CSV files in a single parse pass. Equivalent to running `best`, `trash`, `wishlist`, and `improve` together, but more efficient.
 
 **Output Files:**
 ```
@@ -150,6 +156,7 @@ trash.csv       — Owned cars safe to remove
 wishlist.csv    — Ideal wishlist (very_best unowned, capped)
 add.csv         — Cars to add to wishlist
 remove.csv      — Cars to remove from wishlist
+improve.csv     — Owned cars not yet at final build config
 ```
 
 Supports both `--min-count N` (default 10) and `--max-wishlist M` (default 300):
@@ -197,9 +204,10 @@ The analyzer supports multiple track conditions:
 | `best` | Generate `best.csv` and `very_best.csv` | `[--min-count N]` |
 | `trash` | Generate `trash.csv` (owned cars safe to remove) | None |
 | `wishlist` | Generate `wishlist.csv`, `add.csv`, `remove.csv` | `[--min-count N] [--max-wishlist M]` |
-| `all` | Generate all 6 CSV files in a single pass | `[--min-count N] [--max-wishlist M]` |
+| `all` | Generate all 7 CSV files in a single pass | `[--min-count N] [--max-wishlist M]` |
 | `details` | Print detailed timing data for all tracks (stdout) | None |
 | `track` | Print best car for specific track (stdout) | `<track_name> <condition> <rq>` |
+| `improve` | Generate `improve.csv` (owned cars not at final build) | None |
 
 ### Flags
 
@@ -226,12 +234,13 @@ This generates the following output files (all sorted by car RQ):
 
 | File | Format | Description |
 |------|--------|-------------|
-| `best.csv` | `RQ,Brand,Model,Year,Count` | All cars best on at least one track |
-| `very_best.csv` | `RQ,Brand,Model,Year,Count` | Cars best on ≥ min_count tracks |
+| `best.csv` | `RQ,Brand,Model,Year,FinalBuild,Count` | All cars best on at least one track |
+| `very_best.csv` | `RQ,Brand,Model,Year,FinalBuild,Count` | Cars best on ≥ min_count tracks |
 | `trash.csv` | `RQ,Brand,Model,Year` | Owned cars not best on any track (RQ<80, not prize) |
-| `wishlist.csv` | `RQ,Brand,Model,Year,Count` | Ideal wishlist (very_best unowned, capped) |
-| `add.csv` | `RQ,Brand,Model,Year,Count` | Cars to add to wishlist |
-| `remove.csv` | `RQ,Brand,Model,Year,Count` | Cars to remove from wishlist |
+| `wishlist.csv` | `RQ,Brand,Model,Year,FinalBuild,Count` | Ideal wishlist (very_best unowned, capped) |
+| `add.csv` | `RQ,Brand,Model,Year,FinalBuild,Count` | Cars to add to wishlist |
+| `remove.csv` | `RQ,Brand,Model,Year,FinalBuild,Count` | Cars to remove from wishlist |
+| `improve.csv` | `RQ,Brand,Model,Year,Target,Count` | Owned cars not yet at final build config |
 
 ### Workflow Steps
 
@@ -241,6 +250,7 @@ This generates the following output files (all sorted by car RQ):
 4. **Check** `add.csv` for cars worth adding to your wishlist
 5. **Clean up** `remove.csv` entries from your wishlist
 6. **Sell** cars listed in `trash.csv` that are no longer useful
+7. **Upgrade** cars listed in `improve.csv` to their target final build
 
 ## 📊 Data Sources
 
@@ -318,16 +328,17 @@ struct Car {
 #### Performance Records
 ```rust
 struct BestCarRecord {
-    car_rid: String,   // Car identifier
-    brand: String,     // Manufacturer
-    only_name: String, // Model name
-    year: u16,         // Year
-    rq: u8,           // Rarity level
-    config: String,    // Tune configuration
-    time: f64,        // Track time
-    owned: bool,      // Whether you own this car
-    prize: bool,      // Whether this is a prize car
-    guid: String,     // Game identifier
+    car_rid: String,           // Car identifier
+    brand: String,             // Manufacturer
+    only_name: String,         // Model name
+    year: u16,                 // Year
+    rq: u8,                    // Rarity level
+    config: String,            // Original tune config from JSON
+    normalized_config: String, // Normalized final build (323, 233, or 332)
+    time: f64,                 // Track time
+    owned: bool,               // Whether you own this car
+    prize: bool,               // Whether this is a prize car
+    guid: String,              // Game identifier
 }
 ```