Enforce feature isolation and expand copy_count test coverage

- Gate env_logger init behind #[cfg(feature = "bin-logging")] in
  records.rs main() so the binary respects the feature flag
- Set default-features = false on the dev-dependency self-reference
  in Cargo.toml; previously default features were silently re-enabled
  during tests, making feature isolation accidental rather than real
- Bind guid.to_string() once per card in user_data.rs deck loop and
  reuse it via clone, replacing three allocations per locked card
- Add per-field help text to the Track subcommand args clarifying
  human-readable names ("Laguna Seca", "Dry") vs raw codes
- Document write_details_csv DashMap snapshot memory tradeoff
  (full clone, roughly doubled peak memory during the write)
- Extend my_cars fixture test: duplicate guids count as 2 copies
  with per-copy configs, and incomplete-tune cards still count in
  copy_count

src/output/mod.rs

@@ -249,6 +249,13 @@ pub fn write_trash_csv(
 /// of track, surface condition, and RQ level. Results are sorted by RQ then track ID
 /// for consistent output ordering.
 ///
+/// # Memory
+///
+/// Takes a full snapshot of the `best_cars` DashMap (cloning every key and record
+/// list) so it can be sorted and written without holding DashMap shard locks.
+/// Peak memory roughly doubles for the duration of the write — accepted here
+/// because this runs once at the end of analysis, not in a hot loop.
+///
 /// # Output Format
 /// ```csv
 /// RQ,TrackID,Condition,CarRQ,Brand,Model,Year,Config,Time

src/records.rs

@@ -127,7 +127,14 @@ enum Commands {
     /// Generate details.csv with all timing data
     Details,
     /// Show best car for a specific track/condition/RQ combination
-    Track { track: String, condition: String, rq: u8 },
+    Track {
+        /// Human-readable track name (e.g. "Laguna Seca", not the raw code "laguna")
+        track: String,
+        /// Human-readable surface condition (e.g. "Dry", "Wet"; not the raw code "00")
+        condition: String,
+        /// RQ level (car's RQ up to 113)
+        rq: u8,
+    },
     /// Generate improve.csv (owned cars not in final config, sorted by best tracks)
     Improve,
 }
@@ -152,6 +159,7 @@ enum Commands {
 async fn main() {
     // Default to warn level so library/bin warnings stay visible without RUST_LOG;
     // RUST_LOG can still silence or raise verbosity.
+    #[cfg(feature = "bin-logging")]
     env_logger::Builder::from_env(env_logger::Env::default().default_filter_or("warn")).init();
     if let Err(e) = run().await {
         eprintln!("Error: {e}");

src/user_data.rs

@@ -67,8 +67,9 @@ pub fn load_my_cars_data(path: &str) -> Result<MyCarsData, AppError> {
         for card in deck {
             if card.get("locked").and_then(|v| v.as_bool()).unwrap_or(false) {
                 if let Some(guid) = card.get("cardId").and_then(|v| v.as_str()) {
-                    owned.insert(guid.to_string());
-                    *copy_count.entry(guid.to_string()).or_insert(0) += 1;
+                    let guid = guid.to_string();
+                    owned.insert(guid.clone());
+                    *copy_count.entry(guid.clone()).or_insert(0) += 1;
                     // Extract actual tune config: engineMajor + weightMajor + chassisMajor.
                     // Skip cards with incomplete tune data to avoid false "000" entries
                     // that would incorrectly appear as needing upgrade.
@@ -77,7 +78,7 @@ pub fn load_my_cars_data(path: &str) -> Result<MyCarsData, AppError> {
                     let chassis = card.get("chassisMajor").and_then(|v| v.as_u64());
                     if let (Some(e), Some(w), Some(c)) = (engine, weight, chassis) {
                         let config = format!("{e}{w}{c}");
-                        owned_configs.entry(guid.to_string()).or_default().push(config);
+                        owned_configs.entry(guid).or_default().push(config);
                     } else {
                         log::warn!("locked card {guid} has incomplete tune data — skipped");
                     }