databse wipe

db.py

@@ -204,5 +204,14 @@ def get_stats() -> dict:
     }
 
 
+def clear_sync_data() -> dict:
+    """Delete all processed_zips, uploaded_books, and sync_runs rows. Settings are kept."""
+    with get_db() as conn:
+        zips = conn.execute("DELETE FROM processed_zips").rowcount
+        books = conn.execute("DELETE FROM uploaded_books").rowcount
+        runs = conn.execute("DELETE FROM sync_runs").rowcount
+    return {"zips": zips, "books": books, "runs": runs}
+
+
 def _now() -> str:
     return datetime.now(timezone.utc).isoformat()