Introduce core library model

serato_doctor/models/reference.py

@@ -0,0 +1,27 @@
+from dataclasses import dataclass
+from pathlib import Path
+
+
+@dataclass(frozen=True)
+class TrackReference:
+    """A track path referenced by a Serato crate."""
+
+    source: Path
+    path: Path
+    filename: str
+
+
+@dataclass(frozen=True)
+class ReferenceResult:
+    """The filename-level reconciliation result for a crate reference."""
+
+    reference: TrackReference
+    exists_by_filename: bool
+
+    def as_row(self) -> dict:
+        return {
+            "crate": str(self.reference.source),
+            "serato_path": str(self.reference.path),
+            "filename": self.reference.filename,
+            "exists_by_filename": self.exists_by_filename,
+        }