Simple web backend added with upload/status/process/download API

web/backend/utils/validators.py

@@ -0,0 +1,23 @@
+"""Input validation utilities."""
+
+import re
+from typing import List, Tuple
+
+from ..models.request import TracklistEntry
+
+
+def validate_tracklist(tracklist: List[TracklistEntry]) -> Tuple[bool, List[str]]:
+    """
+    Validate a tracklist and return any errors.
+
+    Returns:
+        (is_valid, error_messages)
+    """
+    errors = []
+    for idx, entry in enumerate(tracklist, 1):
+        # Each entry must have a timestamp
+        if not entry.ts or not entry.ts.strip():
+            errors.append(f"Line {idx}: Missing timestamp (%ts)")
+        # Additional validation could be added here
+
+    return len(errors) == 0, errors