feat: automate exact dedupe and improve web feedback

tests/test_scanner.py

@@ -0,0 +1,21 @@
+from pathlib import Path
+
+from am_deduper.db import connect
+from am_deduper.scanner import scan
+
+
+def test_replacing_file_invalidates_content_hashes(tmp_path: Path):
+    root = tmp_path / "AllMusic"
+    (root / "admin").mkdir(parents=True)
+    path = root / "admin" / "song.flac"
+    db = root / ".dedupe" / "dedupe.db"
+    path.write_bytes(b"first" * 1000)
+    scan(root, db)
+    with connect(db) as c:
+        c.execute("UPDATE audio_tracks SET sha256='old-sha', chromaprint='old-fp' WHERE file_path=?", (str(path),))
+    path.write_bytes(b"second" * 1000)
+    scan(root, db)
+    with connect(db) as c:
+        row = c.execute("SELECT sha256,chromaprint FROM audio_tracks WHERE file_path=?", (str(path),)).fetchone()
+    assert row["sha256"] is None
+    assert row["chromaprint"] is None