Fix review findings: wishlist qualifying count, improve docs, and lint cleanup

- Count only configs meeting min_count as qualifying in the wishlist
  copy-coverage check (previously ALL guid_to_rid entries inflated the
  denominator, producing phantom wishlist entries), pre-computed once
  per guid instead of per record
- Update stale write_improve_csv doc to match single-best-target
  behavior including cross-copy exclusion
- Borrow owned configs for the trash CSV join instead of cloning the Vec
- Build owned_final_configs via filter_map + flat_map without the
  throwaway intermediate Vec
- Remove runtime assertions on literal constants (clippy
  assertions_on_constants) and replace a redundant closure with the
  function reference (clippy redundant_closure)
- Apply rustfmt across the crate and drop a duplicated test-section header

src/commands/mod.rs

@@ -57,6 +57,11 @@ pub async fn run_analysis(
     let ctx = AnalysisContext::new();
     let owned = Arc::new(my_data.owned.clone());
     let car_list = parse_all_times(owned, &ctx, cars_db_path, times_dir).await?;
-    let counts = compute_car_counts(&ctx, car_list, my_data.owned_configs.clone(), my_data.copy_count.clone());
+    let counts = compute_car_counts(
+        &ctx,
+        car_list,
+        my_data.owned_configs.clone(),
+        my_data.copy_count.clone(),
+    );
     Ok((ctx, counts))
 }