# Crate Classification

## Problem

Static crates are manually maintained track lists. Smart crates are dynamic views
generated from rules, so stale-looking entries in them should not be presented as
broken manual references or given the same health-score weight.

## Architecture

Crates carry a `static`, `smart`, or `unknown` kind. Folder provenance is the
primary signal: Serato stores regular definitions in `Subcrates` and smart
definitions in `Smartcrates`. `Compatible by key.crate` is also treated as smart
when encountered in `Subcrates`, based on the original migration case study.

The library loader reads both folders. Health analysis reports all references but
scores only non-smart references. Unknown crates remain scoreable so incomplete
classification cannot silently hide potential problems.

Serato documents the folder distinction in [What is in the _Serato_ folder?](https://support.serato.com/hc/en-us/articles/204022904-What-is-in-the-Serato-folder)
and explains that smart crates are populated from rules in [Crates in Serato DJ](https://support.serato.com/hc/en-us/articles/227561407-Crates-in-Serato-DJ-Pro-Serato-DJ-Lite).

## Edge Cases

- The known `Compatible by key` dynamic crate in the `Subcrates` folder.
- Crate fixtures outside a recognized Serato folder.
- Libraries containing both static and smart references to the same track.
- Dynamic references whose current materialized paths appear missing.

## Verification

Tests cover all three kinds, both Serato folders, the known dynamic fallback, the
synthetic five-static/two-smart library, and exclusion from health scoring.