feat: bootstrap NAS music deduper

tests/test_hashing.py

@@ -0,0 +1,21 @@
+from pathlib import Path
+
+from am_deduper.hashing import fast_hash, sha256
+
+
+def test_fast_hash_same_content(tmp_path: Path):
+    a = tmp_path / "a.bin"
+    b = tmp_path / "b.bin"
+    data = b"x" * 200_000
+    a.write_bytes(data)
+    b.write_bytes(data)
+    assert fast_hash(a) == fast_hash(b)
+    assert sha256(a) == sha256(b)
+
+
+def test_fast_hash_uses_size(tmp_path: Path):
+    a = tmp_path / "a.bin"
+    b = tmp_path / "b.bin"
+    a.write_bytes(b"x" * 100)
+    b.write_bytes(b"x" * 101)
+    assert fast_hash(a) != fast_hash(b)