Fix carried use-sound origin and centralize sound normalization

server/app/items/sound_policy.py

@@ -0,0 +1,44 @@
+"""Shared normalization helpers for item sound/media URL parameters."""
+
+from __future__ import annotations
+
+
+def normalize_sound_reference(raw: object) -> str:
+    """Normalize sound value to empty/URL/or `sounds/`-relative path."""
+
+    token = str(raw or "").strip()
+    if not token:
+        return ""
+    lowered = token.lower()
+    if lowered in {"none", "off"}:
+        return ""
+    if lowered.startswith(("http://", "https://", "data:", "blob:")):
+        return token
+    if token.startswith("/sounds/"):
+        return token[1:]
+    if token.startswith("sounds/"):
+        return token
+    if "/" not in token:
+        return f"sounds/{token}"
+    return token
+
+
+def normalize_media_reference(raw: object) -> str:
+    """Normalize media URL-like value while preserving path/query format."""
+
+    token = str(raw or "").strip()
+    if not token:
+        return ""
+    lowered = token.lower()
+    if lowered in {"none", "off"}:
+        return ""
+    return token
+
+
+def enforce_max_length(value: str, *, max_length: int, field_name: str) -> str:
+    """Enforce max character length for normalized string fields."""
+
+    if len(value) > max_length:
+        raise ValueError(f"{field_name} must be {max_length} characters or less.")
+    return value
+